Just have a clean set of rules, if people find repetitive gaps, add new rules.
For example I have these rules
No copying please
Pretty much covers me from everything, added the advertisement part some days ago as this guy kept spamming his site so I removed all links and reference to it from his profile as consequent.
But I added a rule to 'legitimize' my action sort of and not just being a apricot admin.
And about the whole users will leave part.
If they keep breaking rules and you give them consequences for that making them leave, you don't want them on your board in the first place !
Looking for people who actively play or DM Dungeons & Dragons.
Please PM me, working on a secret project ^^.