Only thing SE can do is giving us a vote kick system, beyone that there is hardly anything that can be done. This is something Cs watchers wont like, adding a kick immunity during cs can be abused by afkers.
Activity based doesnt work, its not hard spam a random button and easy to exploit, both ways.
Blacklisting on 3th party sites dont work, its too big a hassle to search through lists of names to see if someone is worth your time, not to mention easy to exploit, X won the loot Y wanted so X is now on the black list site.