Don't let the haters fool you - they're the same guys who told dropbox that they didn't see the point of their services over sharing usb flash drives.
This is a good idea. Other people could abuse it but this is certainly not abuse, any more than it would be to just file a feature request as an issue on a project. Hope it comes through.
No one said you had to run your for-profit idea on whatever code you come up with. There is something to be said about someone who asks for something but isn't willing to put in the work personally (or only the work they want to do).
1: it's open source snd presumably would be committed to the libgit2 project.
2: it's likely to be useful to others
3: it's central, critical code that isn't well suited to beginners. Of course it should be quality code, it's responsible for storing data.
4: it would strongly benefit from the eye of a Postgres expert, which I am not
5: I do not have money to hire developers
6: I write open source code too so I contribute my time to the public