You can set MC to start with the volume at 100% by going to Tools > Startup > Startup Volume. This will at least reset things if someone messes with the internal volume.
Yes. I had that set, and that is a quasi-solution. It still leads to some confusion occasionally.
Basically what precipitated my original post was that we had some people over a few evenings ago, and we were listening to music with G-Force in fullscreen mode. A friend got a phone call when I was out of the room and turned down the volume in MC with the mouse (a reasonable enough move). When I got back in the room and the call was over, I wondered why the music volume was so low. I went to turn it up on my receiver, but then realized it was already at a "reasonable" gain, and shouldn't be so quiet. It only took me a second to figure out, but imagine if I'd been away on a trip, and the Wife was home by herself...
So, I've subsequently set MC to "System Volume" mode. This makes the volume control in MC essentially non-functional. You can turn it up and down, but it doesn't actually do anything. I can leave it like this, certainly. However, I envision a new situation where the same thing happens, and they try to turn it down
and it doesn't work, which equates to a pretty low Wife Acceptance Factor.
However, if they wiggled the mouse and didn't actually even SEE the volume control in the top bar, then they'd probably realize "it must work some other way" and grab the remote and hit the volume buttons, which works! I must say... This is certainly a relatively trivial complaint. Still, it stands to reason:
1. IF MC is set to have a Digital Connection to a Surround Receiver (AC3 and DTS supported), and...
2. MC's "Volume Mode" is set to System Volume.
Then generally you KNOW that volume control isn't going to work. In those cases, wouldn't it make more sense to hide the Volume Control UI completely (or gray it out or lock it or something), rather than show a non-working one?