who actually pays for staff, product, services, etc? You. You are the owner of the business, you pay the business expenses just like any other business.
Staff = Many franchisors offer payroll services, where you pay them to process the payroll (like ADP or PayChex). The wage money comes directly from you.
Product Sourcing = most franchisors will determine which are approved vendors, but you are the one that pays the vendors.
Read the specific franchise agreement.
The franchisee (you). Just like with any other business.
Depends entirely on the franchise agreement - some companies are more centralized than others. The more central HQ does, the more you pay, but the more support you get.
You do...company pays for things like advertising, they choose the suppliers, they usually provide canned training, etc.
The manager or the owner pays it and orders it