All the skills of the Bounty Hunter from the first levels to the third profession: what each one does, at which levels it is learned and which skills are worth learning.
Here we will list all the skills of the spoiler and give the necessary explanations that will help you in the game.
The professions: the first profession is Path to become a Scavenger, the second profession is described on the page of the class Bounty Hunter, the third profession is Saga of the Fortune Seeker.
The skills learned before the first profession
Create Item (passive): in fact this is the crafter's main skill, but we as dwarves, spoilers though we are, are allowed to learn the first level of it, right at dwarf level 5. It does not rise further, but it lets you learn the first-level recipes, such as steel, Coarse Bone Powder, leather and so on. At high levels we have a lot of mana, so we can help the crafters with processing the simple resources, of which we simply have tons. Besides, in the second-profession quests we have to add a couple of first-level recipes, which the NPCs give us to get through those quests. So let it be, it will come in handy.
Weapon Mastery (passive): raises the character's attack. Three levels of the skill; the last is learned at level 15, and it does not develop further. Here we were really short-changed: even Prophets learn this skill up to who knows what level, and we get nothing. Well, that is understandable: if the developers let us learn it further, we would tear everybody apart.
Armor Mastery (passive): raises the character's defense. Five levels; like Weapon Mastery it is learned up to level 15 and does not develop further.
Weight Limit (passive): lets us haul heavy loads. Three levels of the skill, upgrades at levels 10, 24 and 46. It doubles, triples and quadruples the weight limit respectively. Wow: 100k shots in the inventory are no problem.
Spoil (active): the spoiler's main skill; it lets you extract additional items from spoiled mobs. 11 levels of the skill in all; they are learned at 10 (1st), 20 (2nd), 28 (3rd), 36 (4th), 43 (5th), 49 (6th), 55 (7th), 60 (8th), 64 (9th), 68 (10th) and 72 (11th). I am often asked what the success of spoil depends on. My answer: only on the level difference between the mob and the spoiler and on the level of the skill Spoil. That is, if at spoiler level 56 (Spoil level 7) you spoil mobs of level 59, the spoil will land very badly; at spoiler level 59 it will be better, but still not great; but when you learn Spoil level 8 at level 60, the spoil will land on the same mob almost always and at the first try. Since after level 72 this skill is no longer upgraded, you must enchant it, so that it lands at the first try on mobs of level 80. This matters even more for those Interlude builds where the admins did not bother to change the level of the mobs in the top locations (the Forge of the Gods, the rift and so on) to match the chronicles, and mobs of level 87 run around there, which can hardly be spoiled at the first try without enchanting the skill.
Sweeper (active): lets you extract the items from spoiled mobs. It has one level for everybody, learned at level 10.
Blunt Mastery (passive): raises physical attack when you hold a blunt. Since there is never enough SP for learning skills, and also because I beat mobs with duals and a pike, I learn this skill only when I am going to the Olympiad, or when somebody has offended me. Then I take a little axe, learn all the stun skills and the axe passives, and go to punish the offender. It levels up every 4 levels until the second profession, every 3 levels until level 58, and every 2 levels until the third profession. 45 levels in all.
Boost HP (passive): adds a little HP at each level-up; 10 levels of the skill in all; a must to learn, because there is no such thing as too much HP. The first level is learned at 20, the last at 74.
Heavy Armor Mastery (passive): raises physical defense when you wear heavy armor. A must to learn. It levels up every 4 levels until the second profession, every 3 levels until level 58, and every 2 levels until the third profession. 50 levels in all.
Light Armor Mastery (passive): raises physical defense when you wear light armor. I never learn it, not even for the Olympiad, because I do not run in light armor. It levels up every 4 levels until the second profession, every 3 levels until level 58, and every 2 levels until the third profession. 50 levels in all.
Polearm Mastery (passive): raises physical attack when you hold a pike. A must to learn. And you must carry a pike with you all the time too, even if you run not with duals, like me, but with a blunt. But if with a blunt, you will not have enough SP to learn the skills. It levels up every 4 levels until the second profession, every 3 levels until level 58, and every 2 levels until the third profession. 45 levels in all.
Stun Attack (active): the first stunning skill; it requires an axe in hand. It develops only until the second profession. 15 level-ups in all, from level 20 to level 36. I learn it only for the Olympiad or for PvP. If you learn it together with all the other skills, there is not enough SP. Overhit is possible when using the skill.
Bandage (active): lets you cure the state Bleed, that is, bleeding. The skill has 3 levels, learned at levels 20, 46 and 62. A must to learn, because if you meet a mob with the debuff Bleed, it will certainly hang it on you. Earlier you could use this skill to buff from staves at the Olympiad; now it has turned out that this skill is not a magic one, so now we have nothing to buff with except Noblesse.
Wild Sweep (active): the first active skill from a pike; naturally, it requires a polearm in hand. It develops only until the second profession. 15 level-ups in all, from level 20 to level 36. If you learn it together with all the other skills, there is not enough SP. Overhit is possible when using the skill.
Fast HP Recovery (passive): raises HP regeneration. 8 levels of the skill in all, learned from level 24 to level 74. A must to learn.
Vital Force (passive): lets you recover faster when you sit. 8 levels of the skill in all, learned from level 24 to level 72. In principle I do not usually sit down to restore HP, but critical situations do happen. For example, when you have crushed a strong mob or a bunch of them, your HP is at the minimum, and the mob has hung an irremovable poison on you (hello, shamans in Ketra). That is when you simply have to sit down, because ordinary healing potions will not be enough in such a situation. So I learn it without fail.
Spoil Festival (active): lets you spoil many mobs at once, that is, you gather the mobs into a train and use the skill, which works on the whole heap at once. Whether it lands on the mob or not is another question. 9 levels of the skill in all, learned from level 28 to level 74, level-ups at levels 28, 36, 43, 49, 55, 62, 66, 70 and 74. I always learn it, but use it rather rarely, because the mana is gone in an instant. I use it mostly on group mobs, for example in the Frozen Labyrinth, where the spoil is very valuable. Clearly this skill lacks a companion that would pull the spoil out of all the mobs at once. And it was indeed introduced, it is called mass sweep, but that was only in the chronicles, as far as I remember now, of High Five.
The second-profession skills
Fake Death (aura): the so-called "feigned death", when the spoiler, tired of the attack of a train of mobs, can pretend to be a motionless body so that the mobs stop kicking it. It does not always work, that is, fall you will, but the mobs will beat you up anyway. What it depends on I never figured out, because I almost never use this skill. The skill has only one level, learned at spoiler level 40. For some reason spoilers just love using it in Giran, and drop in a heap on the stairs one after another. The skill constantly consumes MP; when the mana runs out, the character gets up.
Hammer Crush (active): the second-profession stunning skill; it requires a blunt in hand. Along with the stun attempt it deals damage and goes through shield defense. 37 level-ups in all, from level 40 to level 74. I learn it only for the Olympiad or for PvP. If you learn it together with all the other skills, there is not enough SP. Overhit is possible when using the skill.
Whirlwind (active): the second-profession polearm skill; it requires a pike in hand. It deals damage to the surrounding enemies and goes through shield defense. 37 level-ups in all, from level 40 to level 74. I learn it only for the Olympiad or for PvP. If you learn it together with all the other skills, there is not enough SP. Overhit is possible when using the skill.
Polearm Accuracy (aura): a toggle skill, or aura, that is, a switchable skill: either on or off. When it is on, accuracy with a pike rises, and you will miss less. It constantly consumes MP. It is used mostly at the Olympiad, and rarely even there, but I sometimes switch it on in the field, if I am pulling trains and see that my dwarf girl misses often. Naturally, the skill needs a pike to work. The skill has 3 levels. Level-ups at levels 58, 66 and 74. I always learn it, even if I do not use it much.
War Frenzy (aura): a toggle skill, or aura, that is, a switchable skill: either on or off. When it is on, it raises resistance to stun and sleep. It constantly consumes MP. It is used mostly at the Olympiad, and rarely even there: when you can see for sure that the opponent has these skills, or when you have already been slept or stunned once and the mana cost is not critical. The skill has 3 levels. Level-ups at levels 58, 66 and 74. I always learn it.
Wrath (active): hits the CP of the enemies around you when you are equipped with a pike. The skill has 10 level-ups, starting from level 66, every 2 levels up to 74 inclusive. Worth learning only for those who go to the Olympiad, because if you plan to use it in mass PvP, you will hardly reach the enemies. And anyway, what are you doing in mass PvP as a crafter?
The third-profession skills
Health (passive): raises the character's resistance to the debuffs Poison and Bleed. One level, learned at level 76. To my mind it does not raise it much, because those same shamans in Ketra keep stubbornly hanging poison. But I learn it just in case. You never know.
Wisdom (passive): raises the character's resistance to the debuffs sleep and root and to mental attacks. One level, learned at level 76. A must for everybody: sleep and root do not matter much, because they will land anyway, but extra protection from mental attacks will not hurt.
Spoil Crush (active): tries to spoil the mob and deals damage to it at the same time. I never use this skill, because it needs a blunt, and I run with duals and a pike.
Riposte Stance (aura): a toggle skill, or aura, that is, a switchable skill: either on or off. When it is on, it tries to reflect the opponent's attacks and the buffs/debuffs cast on you. It constantly consumes MP. The skill has one level, learned at level 77. It does not reflect the damage dealt to you by skills and ranged attacks (bows, for example). When the aura is on, your run speed, attack speed and accuracy go down. Learn it only for the Olympiad, because otherwise it is useless. And even at the Olympiad it is doubtful, because there you are mostly hit with skills and not with ordinary attacks.
Skill Mastery (passive): has a small chance that some skill is reused instantly or that a buff cast on you lasts double time. Absolutely useless, because during farming you could not care less whether some ONE skill was doubled or not: all the others have to be rebuffed anyway. It makes sense at the Olympiad: what if a skill from the augmentation lasts not 2 but 4 minutes. Though I do not even know whether this skill applies to augmentation, I learn it just in case anyway. The skill has one level, learned at level 77.
Armor Crush (active): the main attack skill of the third profession. To use it you need a sword (one-handed or two-handed) or a blunt (one-handed or two-handed). It deals heavy damage and temporarily lowers physical and magic defense. A critical hit and overhit are possible. Shield defense is ignored. A must for everybody; the skill has one level, learned at level 77. Each use takes 338 HP from you.
Battle Force (active): used on a friendly character, it gives a +1 charge for casting the dome (the fusion skill). One level, learned at level 77. If you do not go to mass PvP fights, it is not necessary to learn.
Parry Stance (aura): a toggle skill, or aura, that is, a switchable skill: either on or off. When it is on, it tries to block the opponent's attacks; physical and magic defense rise, but run speed, attack speed and accuracy are cut. It constantly consumes MP. The skill has one level, learned at level 78. Learn it only for the Olympiad, because otherwise it is hardly ever used.
Master of Combat (passive): raises attack when using swords, blunts, duals, pikes and fists. It does not apply to bows. Raises maximum CP. One level, learned at level 78. Everybody must learn it.
Braveheart (active): restores 1000 CP when used. One level, learned at level 78. A must for everybody who goes to the Olympiad and takes part in PvP.
Earthquake (active): the main attack skill of the third profession. To use it you need a pike. It deals damage and knocks the target off the enemies around you. A critical hit and overhit are possible. Shield defense is ignored. A must for everybody; the skill has one level, learned at level 78. Each use takes 340 HP from you. It does not require taking a target.
Symbol of Resistance (fusion skill, a dome). When used, it raises the resistance to something of everybody inside the dome. It consumes one 
Battle Symbol and requires two Battle Force charges to use. The skill has one level, learned at level 80. What it raises the resistance to I never understood, because I never went to mass fights as a spoiler. To learn it you need the book 
Ancient Tactical Manual: Symbol of Resistance, which drops from the mob Tyrannosaurus in the location Primeval Isle.
That completes the overview of the spoiler's skills. I only want to add that we were badly short-changed on magic skills, that is, there simply are none. Not a single one. So to buff ourselves from buff staves at the Olympiad we have to use the only thing available to us, namely the Noblesse skill. Its reuse is long, so do not even hope to buff yourself properly. Quite often you cannot manage to put on even a single buff before the fight. Such is our hard lot.
True, there are still servers where you can buff from a staff with the skill Bandage, but there are fewer and fewer of them every year.