If I could do 2 out of 3, it would be Cirque and
MVMCP.
If I had to choose only
one, it would be Cirque's "La Nouba."
I've seen several Cirque shows, including "O" in Vegas, and La Nouba is my favorite. "La Nouba," loosely translated, means "party." It is a dream, full of wild and wonderful things, that comes true in the end.
Our daughter saw La Nouba for the first time when she was four, and loved it. She's been twice since (she's now 12), and is still grumpy because we didn't go again last December. Except for the opening melodramatic scene, I don't see anything at all "dark" or "scary" about La Nouba! It's a fun, happy show -- full of action and laughter, with a happy ending. And that's the way I would explain it to a small kid -- the first few seconds are a little "odd," but the rest of the show is big-time fun!
If I was going to pick anything as being a little creepy, it would be men with blue faces, in the dark, making loud musical noises. They're amazing musicians -- but a little creepy to me as an adult! I also don't think young kids will really appreciate the incredible musical skills of BMG. I love them, but it's not the show of choice for young kids unless they are musical child prodigies...IMHO.
But the kids will certainly "get" the energy and wonder of La Nouba. Here's a link to a preview to give you an idea of what to expect:
https://www.youtube.com/watch?v=wM-N3pQl9tY There are other clips on YouTube.
Whatever you decide, have a great trip!