i agree with handefood when it comes to availability of potions. there's just too many that makes alchemy a waste of skill points unless u want it for combo of something else such as making honey. but then that doesn't need alchemy(i think).
if we have criticl hits in RRR, wounds will mean more than just diminished hit points. sure hit points will regenerate in time but crippled leg will still mean that your walk/run speed is reduced a lot. bandaged arm can mean accuracy as well as damage u dish out is reduced as well. that can also mean u cannot wield 2 things at once such as a weapon & an armour or a 2-handed weapon.
regarding mana regeneration, when your intelligence is high enough, why not? after all, that's part of the reason why we put points in it, right? that should be the reward for putting a lot of points in a stat. u develop an innate ability.