[Muirdach]

Actually, what your Head Imm thinks is critical here. If they don't support what you're doing, then you're in a very sticky situation, and one without a clear exit. Yes, you may be a Junior Imm, but players shouldn't be allowed to openly accuse you of cheating and so on. Whoever's in charge should visibly back you up and show that what they're doing isn't tolerated. If that means getting harsh with someone, so be it - but it should be your boss doing that, not you. If it comes from the top, they can't do much about it other than stop doing it or stop playing. To be perfectly honest, if you don't feel like the head honcho supports you all the way, and talking to him or her (your boss) doesn't resolve this, you should resign. Otherwise you'll be caught between a rock and a hard place and you'll just end up getting more and more frustrated.

One thing to bear in mind, though: when you're talking about players insulting newbies or driving each other from the game - that isn't staff vs. them. You have to defend the innocent, as it were. Like you said, it's driving people who have done nothing wrong, away from the game, harrassing them in all different places and so on. It isn't as though someone abused a bug to get awesome exp, or something - it's much more serious. Assuming that you do have your Head Imm's total support in this (otherwise, run now), you can't ignore it, that's for sure. Personally I'd find out who the troublemakers are, get evidence, get a hold of them, and if you get anything less than a complete backdown on their part, drop the bombs. The big ones. If they're seriously driving people away and aren't going to stop, then you have to stop that by any means necessary, really.

Yes, too many punishments will cause future problems, but not doing anything will also cause future problems - it'll embolden them and like you said, they'll find another target.