It is 30 people. If someone's an asshole you ban them. It's hardly a fulltime job. The fact that you took their money could actually complicate your ability to ban them if they really get upset.

I have discord servers of gaming friends that have as many people. I've also managed game servers (like Ark servers) with hundreds of strangers. It's not that bad. Bad people venture in sometimes and you just kick them out. Small communities like this mostly self-regulate because they are so small, people's individual reputation actually means something.