Why do I write that? Because I have been researching a little into what has happened on these forums before this new section got created, and I really, really believe that one main reason why the projects never took off, was: Too many conditions before the first note getting played. Born dead.
After looking at the rules above more in detail, I can say maybe I would make them different, but they make some sense and are in fact good. The first impression is not good.
And we are all sensitive, creative artist souls here. Or Rock&Roll warriors with an allergic reaction to bosses. So maybe we can do ourselves a favor by replacing 'binding' with 'default' or adding 'if not otherwise agreed', or even something funny and welcoming that makes it clear from the beginning that there's choice, it shouldn't remind people of the trauma they acquired when their first real band broke apart the moment their first manager wanted them to sign their first contract.

I found a good, clear starting point and reference for understanding copyright licenses at https://creativecommons.org/licenses/ (no surprise)
Technically, I would even say (correct me if I'm wrong) that it should be ok if there is no agreement at all, because nobody could publish the parts he hasn't created without searching agreement first, no agreement means it didn't happen and everybody is still protected. I could live with it if somebody pulls out and takes the rights to all his parts with him; if that makes the project crash, it wasn't very strong and I should better learn how to keep participants* happy.
*errrh, yes, and if this agreement should be taken serious, then maybe 'participant' is a better word, because in English, the joiner is the guy with the nails and the hammer, aka carpenter