DH has had to use an ECV given hip injuries (he's going for his 3rd surgery soon). He never had to stand in line, as they either let him wait in line in his ECV (only at DCA, where they have wider lines) or had him stay in his ECV near the exit and then go on the ride. He can walk 10-15 steps and get into/out of the cars himself, though.
He doesn't do the Fantasyland rides except for Dumbo, which had a special line near the exit for those in an ECV and then you go in through the exit. As long as you can walk a few steps and climb in/out yourself, I assume you can do all the rides.
FYI, DCA is much friendlier to those in ECVs, as the lines are all wide enough for you to stay in your ECV until the very end when you get into the car. They sometimes have special cars for those in ECVs/wheelchairs. For Toy Story, they just had DH go in the line in his ECV and then go to an area farther back (closer to where you first come out of the ride attraction) and get onto special cars. CMs are very helpful so you just have to ask them what to do, but we never had to use a special entrance or stand at the exit line in DCA.
At DL, like for Star Tours, we had to transfer him to a wheelchair that I pushed to a side entrance, up an elevator, and to the entrance of the actual seating area. DH didn't ride Space Mountain, but I saw a line of wheelchair/ECV folks by the exit where the TV monitors are.
Hope you can still have fun the remainder of your trip and aren't in too much pain.
