I have a excelent but very harsh suggestion how to fix TK issue. It's very simple, it's autokick from server when you TK, intentionally or unintentionally.
I TK sometimes as everyone else, unintentionally of course. I wouldn't mind being kicked from time to time cause I in fact made mistake.
It isn't abusable and will force people to think before they hit, therefore forcing them to play more as a team, less hunting kills and playing only for better k:d.
