Now for my suggestions for balancing the classes. Note that all of these are MINOR and do not involve adding anything else to the game. Any suggestions to "create new glyphs" or "remake classes" are obvious non-starters, so I've avoided all of them.
Fighter - Make his death protection refresh on level up
Berserker - Lower his magic resist and reduce his penalty to cast spells
Warlord - No change. He's strong, but balanced.
Thief - Make his +33% items not spawn an extra glyph or potions
Rogue - Either nerf CYDSTEPP (in a way that doesn't hurt Warlord) or change his damage bonus so that he only gets it at full health.
Assassin - Give him a discount on APHEELSIK.
Priest - Change his 2 health per level to a flat health bonus. Around 15 would probably be good.
Monk - Lower his max resist cap to 70%.
Paladin - No changes
Wizard - Make him spawn an extra glyph, instead of an extra fireball. Maybe soften his damage penalty a bit.
Sorcerer - Make his healing scale with level. I recommend mana * level / 2
Bloodmage - Slightly reduce the GG and Earthmother piety penalty for drinking blood
Tinkerer - Reduce the cost on a few of the weaker items (Venom Sword, Witchalok Pendat, and Martyr Wraps specifically)
Transmuter - Leave him the same. Maybe nerf him more so I never have to play him
Crusader - Make fireballs not reset his damage bonus. Alternatively, have the bonus apply to the Fireball.
Vampire - I'm not really sure. Maybe make his conversion bonus +1 lifesteal and +5% damage?
Half-Dragon - Make poison apply AFTER knockback. This makes Venom Sword actually useful for a class and simplifies things.
Gorgon - The poison after knockback change helps her as well. She could probably use a little bit of Magic Resist though. Alternatively, make ENDISWALL give +10% to both resists.
WONAFYT - Add 15% damage reduction (physical and magical) when you cast it
CYDSTEPP - Make exhaustion completely stop mana regen (until level up)