You are headed for big problems. Everything you asked is something that is worked out between the partners, not from responses from lawyers (or anyone else) who know nothing about the business. When all these details are worked out, a lawyer prepares several documents for the business (initial organizational documents, operating agreements, employment agreements, etc), and any major disputes are resolved at that time. The documents dictate how disputes are resolved later, and what happens if a partner wants out, dies, and among many other things. Without this structure, someone (if not everyone) is going to lose their money, even in a successful business. You are already starting with a dispute, possible money problems and splitting the pot more ways. If this is a viable business, do it correctly. If it is not worth this expense (which does not have to be exorbitant), is it even worth starting and putting money in?
That is a business question (vs. a legal one) and a matter of negotiation. Either way, this will end very badly if you do not retain a business attorney to draft the proper paperwork and do it right. It will cost you much more down the road if you do not.
I would sit down with your partners and an attorney and figure out each parties equity interest and role in the business. Once agreement has been reached, the attorney can then prepare the documents necessary to protect everyone. Good luck. If you need any help, feel free to contact me.