I use the the mousewheel scroll for Melee too, also the right side button from grenades, left side for crouch.
I don't regard them a cheats.
I don't like the mousewheel for fire because it essentially changes the function of a single shot weapon to rapid fire, and an automatic weapon to single shot. I don't like it, but that doesn't mean I regard it as a cheat, I would just prefer that is wasn't possible to do. Other members of my clan use it sometimes, and I can't really tell them not to.
It's a server admin/clan choice of what they think is acceptable in the our servers, in this case majority rules and it's deemed acceptable.
It a shame because I just managed to get the software running correctly that will kick (or monitor) for this bind.
Look out for a piece of software called 'FUD Bind Kicker', you will be able to get it for sure if you are a SGA at PSB, as it written by one of the admins at PsB.
Here of a picture of a test kick done on myself :-