I hate to shoot down your ideas, but here is a more revised, different idea.
Make a warn system. /warn (1-5Reason) (ID) (Extra Comment OPTIONAL)
For example, if someone comes in the server, starts DMing, do /warn 1 4 DMing is against the rules. Please stop.(:
If they get 3 warnings, automatic kick. If they log back on, and get one warning for DMing again, it's an instant ban.. aka, 4 DMing warns = ban.
I know this might not make sense but I can clarify if needed, also the other 4 reasons can be any the admins choose.