I was in your situation a few years ago. Broke ankle August 2019. Was non weight-bearing for 8 weeks. About 2 weeks after I could start bearing weight (in a boot) again, we went on our pre-scheduled Disney trip. I was in my mid-30s at the time and I really didn't want to, but I caved and got a
scooter and I have no regrets (I kinda wish I could have a scooter every time now). Get the scooter. And get a rental rather than a park one. Here are my thoughts on why:
1. At the time I went, I still very much needed to elevate as much as possible. I'm tall so this may not work for everyone, but I rented a model with a Captain's Chair and, when needed, I could park it and put my leg up on the scooter's handle bars to elevate when I needed to.
2. recovering from an injury sucks energy out of you so you're not going to want anything that requires extra manual effort. a wheelchair, if not electric, requires you to push or a family member to push you while doing theme park walking. if you don't have a family member with that kind of physical stamina, you're setting you and your relatives up for problems.
3. it is FAR less likely that people who aren't paying attention (walkers, strollers, etc) will accidentally crash into your leg because it's more protected on a scooter than in a wheelchair. You're also higher off the ground so you have better sight lines for driving. stick to the side of a path, even if it takes longer, so you just have to worry about what is in front of you and one side, rather than both sides.
4. if you're nervous about driving it, keep it on the lowest setting (it's good practice in the parks anyway and for the lines you can take it in, they actually require that you set it to the lowest speed before entering the line) and make sure you drive it around your resort after delivery to get used to it - practice tight corners and reversing. rentals are far more maneuverable than the park scooters.
5. my rental came with "bonus" things that worked great for us - cupholder, front basket for storage, port for charging phones.
6. some downsides to a scooter are: you will have to transfer to a wheelchair to get in the line for a few rides and then, depending on the ride, transfer again from chair to ride vehicle. wheelchair would allow you to go right in the line; you can't take it into bathrooms - you have to park and walk (if you need it, i think you can get something for a rental scooter than will allow you to bring/store crutches or a walker for these situations. i just got as close to the door as possible and leaned on my sister, who would also go in to check if there was a line and available handicap stall before having me get up and walk in); restaurants - you likely cannot take the scooter in. If you have an ADR, call ahead and request that you have a table near a door. Walks to the bathroom may be long. Avoid buffets or make sure a family member is willing to make you a plate (my mom facetimed me from the buffet line while I sat at the table and I just told her what I wanted as she went through). If you're at a quick service, they may be able to direct you to a table near a door or outside where you can drive the scooter to. if it's near a ride requiring transfer to a wheelchair for the line, you may be able to borrow a wheelchair from the ride to be wheeled into the restaurant. for example, they were not allowing scooters in the land pavillion when we were there but they had wheelchairs available for transfer to go inside. however, there's only one very small elevator.
Separate tip - if you're planning on rides, know exactly how many steps you can comfortably walk and then drop the count by about 5. Every CM asks how many steps. Also know if you can do a moving sidewalk if they slow it vs needing it totally stopped. they will do either of course, but they will ask if you can handle slower or if you need it fully stopped.
Finally, make sure you're hydrating really well and that you have your pain meds on hand. also an ice pack. it will swell. a lot. so you'll need to manage that at the end of each day.
We had a car and I had a handicap placard so I can't comment on transportation, but I don't know that there's much difference between scooter and wheelchair in terms of waits and boarding difficulties. i've seen people, if they are able, get off the scooter and the bus driver parks it in the bus for you and then the person just boards like anyone else and takes a seat. however, i am not sure if drivers are required to do this or if it's just been someone trying to be helpful.