I wouldn't recommend using multiple "msg" commands that get sent to the server. Flooding risk.
Use one to send to all the channels/nicks at one time, then take care of local echoing, so that you reduce your flooding risk. If you select to send the same thing to 10 rooms, then that's 10 commands you are sending to a server, and if you do that twice, that's 20 lines. Some networks kill you right there.
