A simple way to explain this is that Enchantresses should have a decreased cooldown for heal, they should be allowed to spam their heal skill. As well they should get +1 mana regen per 20 points in INT to balance this out 5 mana regen with 100 points should decrease the use of potions.

As well Warriors should get the same benefit with STR, every 20 points in STR gives you +1 health regen. This would help make them more useful.

Archers can stay the same as they won't get any +regen bonuses without using equips.

I personally feel mages mainly use mana, and the regen rate currently SUCKS unless you have godly regen equips.

STR should also increase your armor every 10 points = 1 armor.