Sumeron

Free dns hosted elsewhere means they can see your every query and every site you visit. So you’ll be paying with your information. You could just set the DNS in your PC to the local IP of your Pi-hole. That way you won’t need to replace your router. It’ll only work for that single PC though.

I’ve found an instance of Sysadmin ! here, with around 6k members (at time of writing)

I’m guessing Factorio.