This might sound like heresy on this forum, but have you considered skipping Disney for this trip and just doing Universal and Kennedy Space Center? Since you did all four Disney parks last summer, maybe your kids would get more out of doing something completely different this time around.
I have not been to KSC, so I can't speak to that. I took my two oldest to Universal last year, and we loved it! First, only ODS rode Rip Ride Rocket and Hulk. YDS didn't want to, nor did he want to wait alone, so neither of us went. No big deal; they're only a couple of rides. While Universal does have true thrill rides, they're certainly not a requirement.
If Star Tours makes you sick, you will probably want to stay away from the intense simulator rides like Transformers and Simpsons. But there are still many other fantastic rides. The Minion ride is a simulator, but not that intense, and you have the option of sitting at the front on benches that don't move, so it's really just watching a 4-d movie.
YDS loved, loved, loved Men In Black. It's similar to Buzz in that it's a shooting game where you compete with the others in your car. ODS and I favored the Mummy ride. It's an old-fashioned dark coaster that is not intense in terms of movement, but has amazing special effects. The Jurassic World ride was so much fun; much less jerky than Dinosaur at AK.
Both of the Harry Potter worlds are amazing! We spent so much time in Diagon Alley working the windows with the magic wands, and the attention to detail is outstanding. If either of your kids is a Potter Fan, they're not to be missed. The HP rides are both great - a nice mixture of ride and motion simulator, but much less jerky than Star Tours. There's also a cute HP kiddie coaster near the castle, and we rode it over and over at the end of the night when it was a walk on, and we could see everything lit up. The Hogwarts Express is a different ride in each direction with different effects and storylines, and not at all intense; it just feels like a train ride, but like being in the movie.
While Universal does not have as many stage shows as Disney, I enjoyed the ones we saw. The Sinbad show had super cool special effects, and I spent the whole show trying to figure out how they did the stunts. Back in Diagon Alley, we all loved the stage version of The Three Brothers, and I thought the Celestina Warbeck show was great, but it didn't hold the attention of my kids (ages 7 and 9).