Hey! I just got back and I have a 4 and 2 yo. We went to Epcot during EMH, walked on to Soarin, used the rider swap on Soarin twice and the 4 yo got to ride it 4 times, since she loved it. While my husband was waiting for us during the Soarin ride, he took the 2 yo to Living with the Land. My hubby loved it, my son not so much - he was apparently bored. We then went on to Nemo and I don't think you can get a rider swap since all heights are allowed. It was a walk-on for us. The second day we went to Epcot, I used a FP for nemo since the kids loved it so much. Same thing with Turtle Talk - no rider swap allowed and I wouldn't use a FP on that. We had a FP for Character spot, which isn't open until the park's normal time, but we ended up waiting for it at 8:50, saw the characters quickly and changed our FPs to something else.
Here's something I learned while at Disney with the little ones. For those rides that ALL of the kids will not be going on, you should look up which rides have rider swap and only get a FP for ONE adult (or two if the older child will want to go on). When you get the Rider Swap, it allows 3 people to go on the FP line. So for example, we knew my 2 yo couldn't go on Test Track or Soarin because he wasn't tall enough, so I only used two FPs (one for hubby and one for 4 yo). Hubby would get a Rider Swap, go on the ride with the 4yo, give me the Rider Swap, and I would then go on with the 4yo. I then used my available FP to book Mission Space, which neither of the kids would go on. I was too chicken to go on that ride so my hubby did, but theoretically I could have, then gotten the rider swap and my hubby would've been able to go too. I hope that makes sense...
ETA: I would use FP on Soarin, Mission Space, Test Track, Character Spot, Nemo and Spaceship Earth. You can get rider swaps for Soarin, Mission Space and Test Track.
