@Diago Any chat moderator (which by definition is identical to a meta mod here) can access a private room. It is possible to make a room more restrictive, so that even moderators have to be given explicit access, but that option is (obviously) only available to site administrators
Chat might not be an aggregator, but provides a rapid cycle time for watching a SO tag (and should be able to do it more efficiently than an external agent)
Since when has a tool's original purpose been the only way it is used? (Twitter being an example -- never intended to share ideas/links.) But I take the point... The room was originally created to host discussions as well, but never took off.
So, in my humble opinion (ie, not worth much!), @balpha and @Marc, +1 for quickleave and quickswitch being always visible, -1 for esc not clearing title/gravatar notifications. (: