Originally Posted by Kouen (Post 4172682)

.npc files have nothing to do with models/skins, so you don't need to worry about breaking your models/skins by removing them.

A .npc file is basically a configuration file which determines the parameters of a non-player character (for example, the stormtroopers you slaughter in SP). Basically tells them what weapons/powers/items they have, which AI subroutine to work on, how skilled they are, and what they look like.

The only side effect of removing the .npc file, is that you'll no longer be able to spawn that particular NPC. Everything else will work fine.