if i was to try and rank up my destruction on a friendly character, what is the best game level to be on, as in do i do more dmg at the master game level over the novice level, or is it the same dmg just the enemy have more health ?

Difficulty only increases enemy health levels, nothing more. Destruction leveling also doesn't work on non-hostiles.

Destruction levelling works on conjure familiar if you dont want to go out into the big bad world. summon a wolf and kill it with Wall of Fire.

thanks for the replys, think destruction is the slowest to lvl up, im like hitting them like 20 times before i lvl up, with my bow it was 4 hits per lvl up