Hmm, I just checked and the American release aspect ratio for the movie is 4:3. So I'd have to assume that 4:3 was its native ratio.
Edit: Ah, I may have discovered the framerate problem. Since the film was played on Disney XD HD, Disney likely used the American 60hz HD encode and simply converted it to the European 50hz HD, which would have resulted in a frame stutter. Disney could have avoided the issue by simply creating an all new European HD encode for the UK broadcast, but converting the existing encode was probably cheaper.
So there you go, Disney AND the EBU are equally to blame for your poor movie experience.