Hello Paul,
Welcome to planDisney! I'm so sorry that you are dealing with such an issue! Let me see if I can be of assistance!
From what I understand, g-forces can be an issue with rides that have accelerating movement and curves such that you feel the increased gravitational force on your body. Now, there are definitely attractions that fit that description for Walt Disney World Resort but I suggest you read ride restrictions and advisories on the
individual attraction page before you get on. If you look at the description for
Avatar Flight of Passage it has a link to "Safety, Accessibility and Guest Policies" shortly below the ride title which mentions that you should be free of "heart, back or neck problems" while on this ride. The reason is that while this ride uses a screen simulation with special goggles there are some quick movements where you are angled in a downward motion to simulate the feeling of a free fall. You are not falling nor is much more gravitational force pushed upon you but speak to your surgeon if such quick movements or prolonged angling of your body could be an issue. Some rides are described as having "small drops", "big drops" or "spinning". Use these keywords to make the best decision for yourself.
Some attractions I would suggest for each Park:
Magic Kingdom Park: Country Bear Jamboree, it's a small world, Jungle Cruise, Monsters Inc. Laugh Floor, Peter Pan's Flight, Tomorrowland Transit Authority PeopleMover, Under the Sea ~ Journey of The Little Mermaid, Walt Disney World Railroad, Walt Disney's Carousel of Progress, The Hall of Presidents, and Walt Disney's Enchanted Tiki Room.
EPCOT: Any show in World Showcase, Gran Fiesta Tour Starring The Three Caballeros, Journey Into Imagination With Figment, Living with the Land, SeaBase, The Seas with Nemo & Friends, Soarin' Around the World, and Turtle Talk With Crush.
Disney's Animal Kingdom Theme Park: Any animal encounter and exhibit, Visit Conservation Station, any shows, It's Tough to be a Bug!, Kilimanjaro Safaris (some driving on uneven roads), and Na'vi River Journey.
Disney's Hollywood Studios: Any show of course, Disney Junior Play and Dance!, For the First Time in Forever: A Frozen Sing-Along Celebration, and Lightning McQueen's Racing Academy. Many of the other rides in this Park have either a fall, spin, or are aggressive enough that I would not recommend it personally in your situation.
My rule when picking out these rides for you was figuring out which ones I'm scared will make my glasses fall off or can make me dizzy. Now, there could be more experiences you can have but I would confirm with your surgeon first. Don't forget to enjoy the nighttime spectaculars and parades! It's always safe to meet your favorite characters as well so make sure to give Mickey Mouse a big hug for me!
I would also suggest you reach out to the
Disney experts that specialize in disability and ride access questions.
I'm glad that you are making this journey and I hope you get to see and enjoy so many wonderful things.
Let me know if you have any more questions and I will be glad to help!
-Nimmy