GM has no way of setting data for NPCs

This includes adding and removing defenses, and setting DEX and SPD.

I suggest the following interface:
   <gm> npc foo set dex=14
   <gm> npc foo don chainmail

The implementation should probably be something like:
    def cmd_npc(self, params):
        name, rest = params.split(None, 1)
        c = self.getCharacter(name)
        c.execute(params)

This obviously wouldn't work (Character doesn't have execute), but you get the gist.