Is there a way to control the volume of videos being played?
Excellent question, and I've had a quick look through the HH manual and nothing obvious in the video section mentions Volume.
Also, I can't find any examples where Audio is treated separately from Video.
Not directly related, but I did find a nice Teeny-Weeny MP3 Player in shoes tutorial that might be useful to others.
Next stop is to dig into the code I think to see if anything is in there.