A few things:
1) My real name is Barbara Reader. I never think to sign my posts because barbreader is just a shortening of it. OTOH, I suppose somebody might think the name means I read barbs. But, until this moment, it frankly never occurred to me that somebody might read it that way. So, I sort of do sign my posts.
2) I am not a film maker. I am a film librarian. I do not promote making Star Trek Fan Films, I promote WATCHING Star Trek Fan Films. That said, I do suspect most film makers want people to watch their films, and I can't promote the null set of films.
3) I do not claim any knowledge about filmmaking. In fact, I have never even been in a TV audience. To the best of my knowledge, in fact, I have never even been on TV as a part of a crowd in the background. I have certainly never been in a movie, written, directed, or in any other was interacted with the creation of TV or movies EXCEPT to WATCH THEM.
4) Having said all of that, I am a lawyer. I have had phone calls with people who are much more important than I am in this Star Trek Fan Film community, in part due to the fights. For that reason, I think an association with principles could help a lot if it provided underlying rules (which could be varied by any writing) for film makers who are trying to help each other and have disputes.
a). Nothing really replaces a writing, but a set of rules which kick in among all member ABSENT a writing could act as a background and set a standard, e.g.:
(i) If Fan Filmmaker A has obtained permission to rent or borrow the prop, equipment, set, etc. (hereinafter the "ST Widget") of Fan Filmmaker B, and the ST Widget breaks while in the possession of A, it is the responsibility of A to pay for it's replacement or repair unless there has been an agreement otherwise, without regard to it's initial condition. If it is in bad shape when A takes it, it is up to A to examine it and make a side agreement about this, to vary this provision.
(ii) If person alpha agrees to do editing or CGI work for filmmaker A, for free, it is understood that alpha will notify A if they decide to not do this work. It is also understood that alpha will not give the same work to B without telling A that they are having duplicate work done and will pick the better one (or the one that gets done first) later.
Standard contracts for the use of sets, costumes, props etc. owned by others (which can be varied) can also assist these transactions.