I agree with the alltalk idea, but I do find it frustrating to not be able to talk to people who are alive at all sometimes. If one person is dead they're alone until other people are also bad at CS.
Maybe having alltalk text chat might be better, as it would be harder to give stuff away with text than with voice.

I like having dead people be silent because we do have a tendency to talk a lot in the Cafe, and in a game like CS, footsteps and sounds help out SO MUCH. It's a balance between tryhard and hardly trying (amirite). My ultimate goal would be alltalk until 10 people, then no dead people can talk, and at max players - alltalk turned completely off, but dead players can still converse with other team dead players.