if someone could script in some kind of a shout command, so you could type something to everyone playing on any server that would be cool. that way i wont have to sit around waiting for someone to die all the time to join a server.

Use the chat on the home of the site. It speaks to all servers

does it pop up onscreen or hidden away in the console?

A better idea is to make just ONE startmap so its really easy to find other gamers. You just login look around and if someones in a map, hop in and join I wish Q4 had co-op...

There are some mods, I've played Q4 coop mods. I prefer Doom3 coop overall. Try a mod called Last man standing.

Messages typed on the webchat appear on ingame screen, like classic chat messages. They don't stay visible a lot of time, so you can open the console if you want to read them calmly.