If there were a [Volume] keyword, it could be placed wherever desired in the skin.
Tried the [Volume] keyword in Theatre View main.xml - doesnt recognise it (shows as [Volume]). At least I was able to replicate the [Zone] information the tv guide, movie wall, you tube, etc.
I thought could do a work-around by switching to standard view, change the zone and set the volume level. After switching back to theatre view and selecting the movie/music track to play, it still changes the volume on you back to 20% when it starts playing.
There is definately some inconsistancy on how it handles volume. If you start-up, it sets the start-up volume on the current zone & maintains the same when the first track starts playing (correct behaviour).
If you select another zone, it sets the volume to the startup volume for that zone (only if it is the first time the zone has been selected for the current session - expected behaviour). When you start playing a track from this new zone, it reverts the volume to 20% regardless of the startup volume setting, which is definatly incorrect.