when a user is being rude repeatedly, saying slurs, or being toxic then kick them with a kick reason like "being disrespectful". Kicking the user throws them out of the server, if they keep joining back and breaking rules, kick them again until they stop.
Also a last resort if they do not have an online account!
If a user is abusing bugs to duplicate items, is hacking, or is sharing private info to others. Ban them. If they don't have an online account just kick them.
When it comes to duplicating make sure that there is concrete proof that they are duplicating or scamming. (some malicious people may fake and photoshop images so it's best to check pixels or send them to GunGun for checking as they can check trade logs)
Report them to GunGun as only GunGun can ban moderators and trusted users by brute force. Depending on the severity they may get their role revoked or they may be banned.
Be sure to send proof as well!