For answers to questions about making mods, you'll have better luck posting in the http://www.gamesas.com/forum/184-the-creation-kit/--this area is more for talking about existing mods.
In general, though:
1) NPCs have "http://www.creationkit.com/Outfit"--they don't wear what is in their inventory, they wear what is defined by their outfit. So you'll likely need to create a new outfit in the Creation Kit, put the items you want in it, and then set Sorex to use that outfit.
2) NPCs have http://www.creationkit.com/AI_Data_Tab, that define how they fight. You'll need to give him a combat style that reflects his new skills, or create a new style if none of the defaults are appropriate.