As far as the gelding goes- there's big then there's big. When a 16.3hh with a lot of leg and big body actually MOVES (he's not in those pictures, and some day, some time, he WILL actually move probably unplanned!) it's a MASSIVE difference to riding an Arab. I'm glad you're passing. He's very average, and does not sounds like a good fit and has a chronic degenerative condition. Just don't think "oh his movement wasn't THAT big" because it very well may be :) Your daughter does not look secure enough for that. It's funny how you get on some horses and they feel tall but some of the taller ones just don't.