These were some additional questions when you re-posted your question. I'll try to answer some of them:
boakl1968 said:
I will be taking my Peg Perego Twin Aria down with us as my twins are going to be just 4 at the time and even my typical twin isn't up to walking all day. Will my double stroller be allowed into the queues and if so, will I be able to move it around tight corners? Will I get dirty looks for having two little boys in a double stroller in line (if my son with CP has pants on, you can't see that he's wearing AFOs and that there is a mobility issue)? Is there another way to deal with this?
AK and the Studio were built more recently and have much large queues so you won't have any problems at all at those parks.
MK and Epcot are older and some of the queues are narrower, but the ones that are wheelchair accessible (which is most of them) will not be a problem.
It takes approximately 5 feet of space to turn a corner with a wheelchair. Since the wheelchair accessible lines are arranged to have a wheelchair turn the corner, you should have no problem turning corners with your double stroller.
As for stares, you may get some. But, you know that your child has a mobility problem and the person staring doesn't. Most often, WDW uses a bright colored sticker (kind of like an airline luggage tag) that designates your stroller is being used as a wheelchair.
Some may not be aware or they may just be rude.
It won't really matter whether or not your child has any visible disability; there are some people who will decide they need to stare or comment anyway.
My (I guess you could call it favorite) wheelchair story is from when my youngest DD was just over 3. She had a very 'wheelchair-looking wheelchair' - big back wheels. No way it even remotely resembled a stroller, except that DD was very little. As a CM was directing us thru the door in The Land at Epcot, a mother tried to push her stroller through ahead of us. The CM told her she would need to park her stroller because strollers were not allowed into the building (don't worry, strollers as wheelchairs are).
The woman pointed to my DD and said, "She's bringing her stroller in. If she can bring hers in, why can't I bring mine?"
The CM said, "That isn't a stroller, that's a wheelchair."
The woman replied, "I don't care. If she can bring her stroller in, I want mine in too."
At that point, we couldn't move because she was blocking our way. Her DH kept saying "It's a WHEELCHAIR! It's a WHEELCHAIR."
The CM finally got her to move so we could get by. He was still talking to her when we went into the building.
So, there may be people who stare or make comments, but you need to do what your child needs. And, try your best to ignore them.