johann i got some interesting results with that stuff, i leveled from 0 to 20 following rape trains but my paladin ended with +25 HP, +5 MP and like +5 Wis. I think HP and MP stats are based on what others do on you (priests) and potions to restore MP and HP, and since i used my ability a lot it explains the Wis. Everything else was under it, so it seems like the dude's theory may be true.
also @ classes, classes are pretty damn balanced if you ask me. knight is probably the best overall if you take into account STATS, but his Ability fucking sucks compared to others. Warrior has insane attack and good stats, but again the ability sucks. Paladin is like a weaker warrior, but with an incredible ability. Same for the others, overall its pretty balanced imo.