Honestly, I think you're trying to squeeze too much into that first day. Assuming that when you say you're arriving in Orlando at 10:00 that you mean that's when your plane is landing, you should expect to get to your resort between 11:15 and 11:30. I also take early morning flights to Orlando, and because of how early I have to get up for them, I am definitely ready for lunch by the time I get to my resort. Add that time in (plus time for checking in and at least dropping off your carry on bags in your room), and I would think you wouldn't be at the bus stop for TL until 12:30 at the least. For me, 3-4 hours at TL is enough. But then add in going to DTD, maybe spending a couple hours there, then going back to your hotel for a couple hours, and I can't see getting to to MK before 9:00. You don't say when you're going, so I don't know how late MK would be open, but you'd probably only get a few hours (although if it's an evening EMH day, you could get 5 hours), but especially after getting up early to travel and then spending several hours at TL, I think I would be too wiped out to enjoy MK. I agree with staceyrhood about saving DTD for another day.