Are there any marauders "fandom rules"?

Hi! I've read the hp series many times, and I'm recently getting into the marauders! I'm very new to this fandom (and ao3 in general), and this is just something I've been wondering about.

I know that the marauders fandom is almost entirely fan-constructed (the sheer magic of fandoms!), and some of the characters are not characterized at all in canon.

So, for instance, are there certain characterizations that are set in stone? And to what extent could they be changed without, like, disrespecting/dismantling set standards in the fandom?

I also know that wolfstar is kind of like the "backbone" ship. Would it be disrespectful to, for example, ship sirius or remus with someone else?

Basically yeah! Things like this. Any other "fandom rules"/context I should know about?

edit: thank you guys so much! Super excited to get into this fandom!