For Fantasmic, I'd suggest getting there early and securing a table at the Riverbelle Terrace. It's not the very best, unobstructed view, but it is pretty good. Add the bonus of having a table and chair, and it's the best seat in the house IMHO. Also, check at City Hall and let them know your situation. They may be able to get you into the handicapped seating area, which may have seats (but I'm not sure about that).