I’ll be on this cruise too! We’ve done this itinerary many times (minus La Paz). I’ve read many of your reviews when your baby was a wee mermaid.
1. I went to Rhythms of the Night a few years ago on the Panorama. It picked up us right FROM the actual ship. Like you do with a tender boat- except you get on their boat. It headed directly to the island from the ship. It dropped us off there too. It was useful since there was free alcohol.
2. Yes. They have plastic chairs. I suppose they have the potential to be rickety like all plastic chairs. I’ve never seen anyone fall. I’ve been to the island 3 times and I’ve never seen an accident. Yes, it could happen, but anything can happen on a moving boat.
3. RotN is dinner and a show. My kiddo loves theater and music and all things related to performance and having a good time. The boat ride over is loud music, drinks, and great views. The island is dinner buffet style and then a short walk to the theater. The ride back in the boat is another show put on by the crew and lots of dancing. Even my shy kid was in the dance area doing the Cupid Shuffle. Do your teens like all the kinds of activities by the pool? Do they like watching acrobatic shows? If no, this might not be their jam.
4. The food is fine. Not memorable or super amazing. But you’ll likely find a few things you like and you can fill up on that. There’s lots of choices and my ADHD kid who I feel only eats 5 things always finds something.
5. The outdoor theater does not have chairs. If you have back problems, then, yes this can be uncomfortable. I’ve never thought of this before but yes it’s true. The show is truly spectacular and captivating. Check out YouTube- lots of people’s videos have a glimpse at the actual theater—and the boat.
Honestly, having read about how adventurous your family is in the past— you might NOT enjoy this unless you go in with the idea that this a relaxing, fun, silly time. I love it and am sad not to do it this cruise, but I do recommend it. However, you know your family best.