I opened up the geck to see if the eyepatch NPCs sometimes have is an item that just isn't in the loot table, but it seems to be an actual part of the body.

I was wondering if I could take the information here (the NIF) and simply move it into a new item I can make wearable so I can have an eye patch on my player character?

its alrdy been done
http://newvegasnexus.com/downloads/file.php?id=36087

Does it add them to the loot table, too? Or will those NPCs that spawn with an eye patch still be some weird mutant with an eye patch as part of their actual face?

Dont think its added to the loot table, only now u can buy it in goodsprings