so i downloaded a mod that puts the spellforce 2 char nightsongs armor into the game its classified as light. i was wondering if i could use it melee without getting cut to pieces or pounded into dust. ill be using longblade and the armor if you wear all the pieces give you 52 AC

If you're good at it it'll protect you well like any other armour. If you're better with heavy armour you could always change the setting in the Construction Set, though.

i have heavy armor as a minor, and plus i like glass more then daedric anyway. is 52 armor rating good?

It's decent for a new character, yeah.

i also have another question probably stupid but im going to ask it anyway, do the creatures you kill in the wilderness and dungeons respawn?

NPCs do not respawn. (except for a very few select cases)
Creatures do respawn. They will respawn in 72 in-game hours if you do not Dispose of Corpse... but if you do Dispose, they will respawn as soon as you leave and re-enter that cell.

Really? I never knew that and merely assumed all dead enemies respawned upon reentering a cell no matter what. It actually kind of hurt immersion a bit, so this will help with my latest roleplay.

NAMED NPCs don't respawn. Unnamed NPCs, such as Guards and Ordinators, will respawn. Creatures do not necessarily respawn as the same type creature. (e.g. A dead rat might respawn as a scrib or a Dremora as a Golden Saint).