> he being the one with the idea and money

Ideas are worth $0. Nevermind you'll switch the idea to something else.

And the type of person who wants to a get patent first instead of getting users is precisely the kind of person you shouldn't be starting a company with. A patent won't get you customers. How many companies can you friend name that lost to another company because of a patent rather than a thousand other reasons?

Both your fears are valid. Trust your gut. My suggestion: don't start a company with this friend.