Joining the cops with the quiz lets people make a new account and abuse with that. Since it is a level 0 alt account the abusers lose nothing from having it banned. You should also have to claim officer at level 4, and just remove ERT. The team ERT can just be raised to Commander. This would cause most of the abusers to at least have something to lose from getting that account banned even if it is an alt.
I have to say, removing ert would be terrible. Maybe don’t remove the quiz but then after passing you get a role showing you are not a cadet yet, but like a trainee role but without needing a training. Oh and also you HAVE to become level 2 to finally become a cadet. All the quests give a crap ton of exp anyways, and I’m pretty sure you can do 3 of them multiple times (from my experience)