Had to chime in with a few things.
I had noticed your DD Queen shirt earlier...don't know if she's a fan or just likes the shirt - but if she is - very good musical taste for a teenager!
Normally there is no music in the queue area of R'n'RC. You are supposed to be in a back alley of a recording studios waiting for the limo to take you to a concert, so there wouldn't be any music there.
I agree the ride is way to short. This is part of putting a coaster with inversions inside a building...the ride can't be very long. I also agree with your DH - since they put it in the dark, the inversions aren't very impressive. My favorite part of the ride is the launch.
And there's a very simple reason that TSMM is so popular - EVERYONE can ride it. Think about the total # of rides at DHS - ToT, RnRC, TSMM, ST and GMR. Five rides total. Two of them are purely for thrill riders and Star Tours has some limited appeal that way as well. That leaves GMR and TSMM, and regardless of what you think of GMR, it's not one that has a lot of repeatability. Since a lot of people come to Disney for the rides more than anything....TSMM draws huge crowds because of what the competition in that park is. But it's the ride that Grandma, baby Danny, Uncle Sam and teen Darla can all ride and have a ball on. You saw this reaction yourself - that coupled with there's nothing else in DHS to compete. If TSMM was in MK - it wouldn't draw nearly the crowds. (Why the one in California doesn't draw as much.) It's just an example of how badly DHS needs rides.
Also, your shot of the entrance of RnRC where you describe as "plenty of people around", that's a pretty empty shot in my view. But it is pretty typical that the number of people walking around the parks looks much worse than the number of people waiting in lines for rides. I don't know why that is true, but it is!
Enough of my rambling...it's your TR, not mine!