Sadly yeah. We absolutely should use email signup because it filters our the absolute lowest effort bots, but it does nothing against higher quality bots or humans. Not only can you easily spin up new emails on the fly, but many emails allow ways to make the email appear unique (eg, Gmail ignores dots and anything after the + sign), there’s plenty of temporary email services with a variety of domains, and if you own a domain, you can trivially create unlimited emails until they catch on and ban the entire domain.

Inactive admins are also an issue, but if malicious users are determined enough, it doesn’t matter that much how active an admin is. An active admin can mostly help by making IP banning an option (imperfect, but will work on many humans) and can temporarily turn on approvals to make it easier to weed out low hanging fruit. Nothing will work against someone determined enough, but could at least reduce how many instances they can turn to.

Yeah. A troll might post something like a ton of oversized images of pig buttholes. Who the fuck even has access to CSAM to post? That’s something you only have on hand if you’re a predator already. Nor is it something you can shrug off like “lol I was only trolling”. It’s a crime that will send you to jail for years. It’s a major crime that gets entire police units dedicated to it. It’s a huuuuge deal and I cannot even fathom what kind of person would risk years in prison to sabotage an internet forum.