It's not all that thorny really; you don't get any money from your third party patches. The indiegogo funding is for three man years of funded development work split between two men. It's opensource so you are free to help out if you want, just don't expect to be paid.
I seem to recall a recent study that suggested paying some people explicitly for their open-source work (versus scratching-an-itch) had the effect of discouraging contributions from everyone else. Unfortunately my google-fu is too weak right now to find a reference.
