-Hunter damage is low, give them steady shot and take out another spell they have.
-Mage damage is fine, but their spells cost too little mana.
-Warlock damage is extremely low, give them higher rank DoTs.
-Rogue damage is high, fix gouge, it gives 5 combo points and it should only give 1.
-Paladin DPS is extremely low, try giving them crusader strike and divine storm.
-Paladin healing is extremely high because their flash of light cost 28 mana and heals 200-350.
-Paladin tanking is extremely bad, try giving them hammer of the righteous and holy shield.
-Druid healing is fine
-Druid tanking is terrible, they need a lot more armor and dodge. Maybe dire bear form?
-Druid cat form DPS is terrible, they need some kind of burst, maybe tiger's fury and ferocious bite.
-Druid caster DPS is fine.
-Warrior DPS is fine BUT they have no good way to move, I suggest giving the protection talent, Warbringer, to all warriors.
-Warrior tanking also needs Warbringer.
-Shaman healing is fine.
-Shaman melee DPS is doomed. Don't bother trying.
-Shaman caster DPS is fine.
-Priest healing is fine.
-Priest DPS is low, they should get a quest to earn Shadowform or Vampiric Embrace.
For classes or specs that need a buff, I suggest a class quest that gives them main spells that will help them do better damage/healing.
For classes or specs that are too strong, they are usually just bugged