Great idea to watch videos of anything you have questions about!
The one thing I'll share about Peter Pan though is that even though I've ridden it a lot in the past, I didn't really have a memory of how dark it was for the passengers until this most recent trip. We took DS (11 months) on it for his first ride, and he cried the whole time - I'm pretty sure because he couldn't see me or DH. And the hardest part for me was that I couldn't see him either! We could feel him as we held him close to comfort him, but we couldn't see anything for almost the entire ride except for the parts of his outfit that were glowing in the dark. Poor baby... So if your child is sensitive to the dark in that kind of way where it would weird her out to not be able to see your face, just keep that in mind.
Other tame things we find fun: Country Bear Jamboree, Carousel of Progress, the Railroad, Tom Sawyer Island, Swiss Family Treehouse, and Peoplemover (which does have periods of dark, but not extended).
Have a great trip!