I'm thinking, based on advice here, that the best scenario would be for me to set myself up as a separate biz, legally, and just pay him rent. I get my own FFL, which should be doable seeing as BATF has inspected the shop and licensed him 3 months ago. Keep my own log book for BATF, and keep my owns set of books for tax purposes. That way it seems I can protect myself from being involved with it if he goes belly up. Rent is also tax deductable and work in trade is not. I can work my own posted hours. I don't even want to be involved with the reatail side. Don't plan on it. Being a partner is out of the question. I want my own space to do my own biz. I'm in a downstairs part of the shop so that will limit the BSer's stopping by. I plan on only being open 3-4 days a week for now, and if I need to get something done badly I can just go in and lock the door to the upstairs or do it in my home shop. Getting a lawyer involved would be looked on as "City". This is rural western PA, and a man's word and a handshake still mean something. Although I will consult privately with one and ask him to draw up any agreements.
Keep it coming you all have been encouraging and enlightening.
thanks