About 2 or more ppl in support room:
JMO, there is private chat option, so I don't see any problem when there are several ppl in the support room. The 2 ppl who talk can switch to "away" and move to private chat, and that's it, the conversation will not be interrupted ant the 3rd one who joins the chat sees that the other ppl aren't available.

Re Ts on call: I get the impression than most ppl here have their own Ts, so I don't think we need additional T here as most of the Ts are available for emergency calls from clients.