Its guys like you ruined it for everyone else.
Exactly the reason I stopped playing pugs (plus the fact that many other quit too...for same reason possibly)... People started taking them way too seriously. Honestly i'm not too sensitive or anything, I don't take stuff personally but it's just not fun anymore when people take stuff too seriously and cry if they're losing/die from a lucky shot/whatever.
Force teamsay only to avoid spam/flames? Bitch on irc afterwards if necessary... I realise theres togglemute for mute enemy-function but guess what, you get laughed and flamed at for using that too although then people would probably start changing their nicks to get their point through... Maybe force league nicks only too? I don't think people would go as far as switching to other team's teamspeak to flame somebody but honestly I wouldn't really be surprised if they did...
Just a few ideas, although too much forcing could take even the last fragments of fun away from pugging.