If you want it to be constantly admined and limit the abuse of it.
Restrict the rights of those that aren't to be trusted to the bare basics, don't allow them to ban, freeze, burn, teleport people like they have been doing.
This allows them to talk through admin and kick if necessary, allowing for there to be control in the server.
And if someone is found to be hacking, tell them to take the steam id and tell a more senior admin with the privileges to ban. (They can kick in the mean time)
And if they are still plain abusing, take the admin off them and if necessary show them the door tbh.