Only the skills which have overhit in their description can overhit. Read the skill descriptions...
Overhit is just the extra damage you deal on a mob converted to XP. It doesn't depend on critical hits and it doesn't affect them. Obviously, if you overhit with a critical hit, you get more XP. The amount of XP from overhit is capped to 25% of total XP (last time i checked this was a long time ago). It's useful only for solo exp where the benefit is noticeable. It's useless on mobs with high HP like mobs in group xp locations and bosses.
Only the skills which have overhit in their description can overhit. Read the skill descriptions...
Overhit is just the extra damage you deal on a mob converted to XP. It doesn't depend on critical hits and it doesn't affect them. Obviously, if you overhit with a critical hit, you get more XP. The amount of XP from overhit is capped to 25% of total XP (last time i checked this was a long time ago). It's useful only for solo exp where the benefit is noticeable. It's useless on mobs with high HP like mobs in group xp locations and bosses.
Not true. Pressure punch overhits, and the description doesn't mention over hit at all.
Likewise when heavy punch procs and kills the mob, it's an overhit, and yet the passive skill description says nothing about overhit at all.