As for the GAC only being for those with cognitive disa, That is what I was told by Disney when I wrote them when the GAC was first introduced. I know I no longer have that email, as I deleted it once it was outdated information.
I will have to see if I can find the link to the court order (thinking about it, it may have simply been a settlement, but it was still legally binding) to expand the GAC, back in the day I kept a copy with me when going to the parks. But this was many years ago and I am not sure where it went off to, but I should eventually be able to dig it up. Won't be for at least a few days though.
Edit:
I found some of the information:
I honestly can't remember all of the details, but it was related to this case, or rather to the incident that the case is about:
http://www.care2.com/causes/disneyland-sued-for-leaving-disabled-man-on-its-a-small-world-ride.html
There were actually a lot of changes, at least at Disneyland that were related to the original incident, some were due to court orders, many others were Disney trying to show that they took the complaint seriously.