I'm too much of a scaredy cat -but I guess you could just tell them up front that you have ADRs even if you don't. At MK w e've never been asked for any kind of proof or anything.
I agree.. making any ADR and having no intention of showing is pretty inconsiderate. I have a friend who does this and it just ticks me off. At places like Crystal Palace there are lots of families that would love to have that spot for legitimate reasons.I don't recomend making an ADR just to get inside that park early. It's not fair to the people who really want to eat there and you run the risk of being asked to leave and wait outside.
For Donald's you are escorted by a Cast Member to the restaurant. You are not free to walk around the park. Even if you finish eating early you are held back by Cast Members at ropes until the park opens.
I went to Donalds before the park opened and I was not escorted by anyone, they just told us where to go...there were ropes up blocking us from going anywhere else