I had to have a scooter for the first time on our last trip. The CMs are all wonderful. They said to look for the red umbrella at each ride to arrange return times, and there was only 1 ride of the ones we went on (I cant recall which) that did not, in fact, have a red umbrella associated with it.
Yes, the Star Wars rides' lines you can drive through and all the rides in CA. I had no problem with the turns. The one ride that may be problematic is Space Mountain. On our prior trip they asked if I could do stairs and I said I'd prefer not to but they explained that would mean I might have to wait a long time the way it was set up, so I did the stairs so my family did not have to wait. And even before that trip, they asked if I could get in and out of the cart in some number of seconds and I said yes because based on a prior experience, when the CMs decided I would need more time without asking me (and I didn't at the time), they had put me in a handicap cart on a siding and waited till it filled up before sending it off, so the rest of my group was long gone! This last trip, I just skipped the ride (and was able to interact with a cute little robot, H.E.R.B.I.E., outside).
It sounds like you are staying on property so there is only one scooter rental place they allow to deliver the scooter to your hotel's bell service, which is a big plus so it can be there waiting for you. Hopefully they allow you to leave it with the bell service for pick-up, too.
While the CMs were wonderful, I can't say the same for park visitors. So many of them act like you are invisible, cutting in front of you at every opportunity, so I was forever being separated from my group, while others DO see you and decide you are the perfect person to cut in front of because they feel you should stop for them since they are more important than you My next time in the parks without a scooter I will be sure to be more respectful of people in scooters as long as they are are moving with the speed of the walkers and not faster, which is what I tried to do. I especially disliked when a whole wall of visitors going against traffic would walk straight at me (or a whole family) with no place for me to go.
If you like Fantasmic!, the Rancho meal was decent and reasonably priced, and their viewing area was great, good angle and I liked the fact that is was not too deep, so even though I was in the back on my scooter and my family was in the front (on the ground ugh!) I really wasn't too far away. And I had a great view and the most comfortable seat in the house!
Have a wonderful time.