First, I have a massive headache from just reading this thread in its entirety
Second, I really like this idea except for a few things;
-Student: as has been mentioned its a PLers dream
-Bonuses: someone (not gonna search for name) pointed out that heroes have weaknesses. I like this idea so I'd think your weaknesses in categories could be like this:
Student: While you are a quick learner you have difficulty grasping concepts without others help. [- some % xp when not teamed]
Mentor: You're a great teacher and your underlings excel when you are near. However, when they're not around you, you are lonely[-some % defense maybe? or perhaps accuracy? just throwing out some ideas]
Rogue: While you excel at crime your name is well known and the authorities are a little less kind to you [gain more debt from deaths]
Merchant: You're good with money but all that wealth makes you an easy target for other criminals[mobs' aggro range is doubled on you]