I have two main builds Archer/Psych and Pig/Psych both work very well at top level. I have played many different skills combinations up to current top level with max enchanted gear.
I strongly suggest that new players should not play any of the animal forms until they have a good grasp of the game, it severely limits the NPCs they can interact with and greatly impedes acquisition of skills, money and storage.
My view on the current skills follows:
Animal Handling
Currently broken; your pet at high level is well nigh useless or worse than useless as it can aggro stuff you do not want in a fight. Needs a major overhaul.
Archery
Probably the strongest DPS skill in the game, huge damage potential both single target and AOE, plus it's ranged! The down side is you will be making arrows continually and you have to carry several different arrow types in your inventory; not to much of an issue for higher levels but very expensive and somewhat limiting at lower levels. Monsters that reflect damage can be deadly for archers. I suggest adding more monsters in future that are resistant to impaling damage.
Bard
Good DPS, good buffs both for party and excellent single player buffs, some healing. Requires poetry appreciation to level. The biggest issues are that you have to stand still to generate tunes and the best buffs are very short term. I would suggest the removal of the stationary tune generation and an increase in duration of the best single target buffs.
Bat
A skill i have not played. From what I have observed it is reasonably balanced in DPS and it does give you flying without being a druid.
Battle Chemistry
A nice mix of control, damage and healing along with some of the best speed buffs in the game. Some of the best armour buffs in game. No changes needed.
Cow
The best tank build you can get along with the highest speed of any character. Cow can generate huge amounts of aggro and take a lot of damage at the same time as generating reasonable DPS.
Deer
An all rounder, good speed and reasonable DPS you will also be able to jump higher than any other character class. I would suggest a mild buff to damage.
Druid
Some excellent debuffs, a very good nuke and some good healing skills. It also allows you to turn in and out of deer and bird forms at will. Many people take druid solely for the ability to get bird forms and fly at level 50 which makes surveying in Kur much easier. No changes needed.
Fire
Good AOE ranged damage, slightly subpar DPS, over the top aggro generation, somewhat power hungry. Rather like the poor mans' archery and by comparison it loses in every way. It's playable but the damage needs to be buffed and the aggro generation reduced.
Hammer
Good DPS with very good stuns. No changes needed.
Ice
Average DPS and excellent crowd control along with some methods to mitigate damage taken. No changes needed.
Knife
Although i have this a top level i have never really used it. The damage output appears to be a bit low.
Lycanthropy
Excellent DPS, possibly overpowered in a pack, huge armour available through crafted metal armour, this advantage will be reduced when crafting of metal armour for other classes comes in. Note that for three days each month you must be a wolf and you cannot get out of this, if you like playing melee DPS this is not a great detriment.
Mentalism
Very good party buffs and good healing sub par DPS. No changes needed.
Necromancy
As broken as animal handling; basically your pets do not do enough damage and are taken out in one hit by higher level monsters if they manage to generate enough aggro to even be hit. Needs a major overhaul.
Pig
Excellent party buffs, excellent crowd control, very good healing, sub par DPS. Probably the best party support class in the game. No changes needed.
Psychology
Very good healing, an excellent nuke, some individual control (single mez and single fear). No changes needed.
Rabbit
I have not played this nor have i seen a fully kitted out end game build. Damage appears to be sub par, good speed and good pulling abilities but I cannot comment further.
Shield
Great stun and the best early game speed buff you can get but damage is low and other support skills are better. Needs a buff on it's armour regeneration skills to make it viable.
Spider
Another skill I have not really played, DPS appears to be good but i have not enough experience to comment further.
Staff
Excellent damage mitigation, a stun and average DPS. Often used by archers to counteract reflect monsters. No changes needed.
Sword
Excellent single target DPS. No changes needed.
Unarmed
Good DPS and good stuns, can be excellent if you are prepared to lose a chunk of your armour to double your DPS. No changes needed.