It is probably better not to hit the franchisor with these all at once – you will almost certainly have several meetings with your potential franchisor. However, you should ensure you get answers to all the relevant questions before signing the franchise agreement. If you buy the franchise, you will be entering into a long-term relationship with the franchisor, and it is therefore important that you should go into it with as full an understanding of the business, its potential and your mutual obligations as possible.
A good franchisor will welcome thorough questioning, as it shows that you are serious. Most franchisors should have a disclosure document which will include many of the answers, and you should read this thoroughly and discuss it with your professional advisors.