We know what this will come one day, but I through it would be a good idea to go through more advanced features and share them from my perspective and experience running forums.
1. Groups
Every new user should be by default in "Quarantine" group. This group does not allow user to change avatar, profile information, or any other information expect email/password. User can post, but posts won't be visible unless admin/mod approves it. It should be possible to define how many approved posts user needs to move away from "Quarantine" group to the normal one.
2. Moderation feed
Admins/mods should have separate moderation feed to simplify and make quick approvals/bans for new posts/threads. Nice option would be to have browser/email notifications. Perhaps even direct links to approve/ban posts in the email. This tool should also show approved posts.
Bonus points: Send automatically "Edited posts" back to the moderation feed.
3. Freeze inactive accounts after X time
This is big problem in big communities. Many people re-use same passwords, they get leaked and after that spammers might use to bruteforce it and try to get access to the user account. If user was inactive for long time, Waterhole should send verification link to the email that will approve authorization.
Alternative option would be to implement 2FA and have an option to force it on all the new users accounts.
4. Lock "edit post" after X time
Each community can decided itself what is a fair amount of time to edit the post. To make this even better there should be exception depending on the user group. Some groups might not be mods, but still manage some pinned posts that require frequent updates. This feature is important so spammers won't replace legit posts with spam later on.
5. Ban and warning system
I think it is enough to have 2 options permanent and temporary ban and possibility to specify why user got banned, so the person who broke the rules knows what he did wrong. Additionally it would be a nice to send warning first to the user, instead of doing instant bans. Hopefully Waterhole won't implement IP ban, because I find them ineffective and it can hurt users who use VPN/proxies. People can bypass it easily.
We should be able to warn users first, instead of doing instant bans. If user is banned he should have a visible message with reason of the ban. Could be canned options or custom message. Same goes for warning messages. There should be two type of ban options: permanent and temporary.
Hopefully Waterhole won't implement IP ban, because I find them ineffective and it can hurt users who use VPN/proxies. People can bypass it easily. Same goes with trying to fight temporary email services.
... I think that's it. I probably missed something, but that's a good start.