This was our experiences with some of the attractions: (I'm only listing the ones that my friend and mom did)
Jungle Cruise was great - able to use the wheelchair on the boat
Pirates', a bit of a problem for mom getting into and out of the boats - doable with help though.
Splash was good for my friend, no problems at all (mom didn't ride)
On Haunted Mansion, they took us to a separate area and we were able to wheel her to the ride vehicle so she could get out and get on. They stopped the walkway as well.
Small World had a wheelchair boat as did Under the Sea
Mine Train was pretty tight for him and he was very uncomfortable throughout.
Buzz Lightyear - wheelchair vehicle
Mickeys Runaway Railroad - no problems riding for either, mom did have to get out of the chair to enter the car but had no problem
Millennium Falcon - no problems at all, able to use the wheelchair up to the ride vehicle
Toy Story Mania - wheelchair car - no problems
TOT - mom did not ride. A little tight for my friend but they put us in the front row so that we would have more space.
Navi River Journey - again, a small issue getting in and out of boat for mom but she did ok.
FOP - Mom was able to ride but my friend had to leave the ride area because he didn't quite fit

Safari - able to use the wheelchair on the trucks
Dinosaur - mom didn't ride, too jarring for her. Friend was able to ride with no problem
Spaceship Earth - handicap entrance, they pulled the wheelchair up to the ride cars - it was pretty tight getting in and out for both due to the narrow doorways
Finding Nemo - wheelchair vehicle
Soarin - Could take wheelchair right up to the seats, no problems for either buckling in as long as the belt was pulled way out first.
Three Caballeros in Mexico - Wheelchair boat
Ratatouille - No problems getting in or out but the ride made my friend very queasy due to some scenes zipping by really fast.
Living with the Land - Wheelchair boat
Unfortunately, we didn't get to ride Test Track, it was closed due to storms in the area.
Thank you all, you've been so helpful and I hope this helps someone else out in return!