I would have the following questions,
1. do you have to sign a contract to pay him your 400 nut regardless of how he is selling his end?
2. with his expansion plan does he have partners that could come in and change things on you.
3. as a independent what are the costs for insurance since he can claim anyone your working with that gets hurt and sues is your fault and not under his insurance.
4. have you gotten the cost structure for setting yourself up a inde business so you can keep your personel assets out of the line in the event somebody sues.
5.does the owner have the capital to make expansions
6. what is the per capita income level of the area you will be working?
7. how many clients and at what fee structure is you break even point?
8. are there other gyms (franchised big name) either in your area or that could put pressure on your client base.
9. as a sole propriotor what happens if you are injured and need time off who will cover your monthly nut?
10.how much time do you see yourself investing and when doing the math with your break even point is it a good investment.
11. is there any bonus or commission for you for anybody you bring to the table for the gym?
12. what are the gyms short term market analsis for prospects and when they reach there threshold or break even point.
13 does the owner have experence
14 banking considerations for your new company
15. time away from family since allot of clients will want to train in the evening or early morning.
just to name a few