You make good points, but each of these is solvable: 1) Require the code to be consistent. Tell the submitter how to do this. 2) Merges have to be straight fo

You make good points, but each of these is solvable: 1) Require the code to be consistent. Tell the submitter how to do this. 2) Merges have to be straight forward, or you don't accept the submission. I think Linus Torvalds has the same strategy for the kernel - you figure out the merge, I'll accept it. 3) That depends a lot on how you set up your tests and documentation. If you make it simple to write both, it's simple to require them. If they're not simple, you should make them.