I haven't had a single problem with Thorn..
He kept spitting on me with a Granger once but i didn't really care, i bet he would stop if you ask nicely though.
Sure he can get cranky sometimes, hell i get cranky a lot more then he does and nobody kicks me for it.
There are more important things to kick/ban for, also
SO: Make up strict rules that apply to everyone, Thorn will either follow them or accept the consequences.
ALSO: Thorn isn't using an aimbot, if he was, he'd have a fire/hit ratio of at least 10:9 which he doesn't have.