Believe it or not, it's not that busy crazy in the early morning! I think some people have this vision that it's like the running of the bulls in Pamplona, small children being trampled......
We do am EMH at all of the theme parks other than MK in summer and then head back to the resort at 12-12:30, by then the sun is burning hot! The parks start to get real busy 9:30 to 10:30 when the rest of the people get to come in.
MK we do pm EMH, the park is open till 2am, we get up late that day and relax at the resort, head out about 4:30pm and do MK till late! It's doable with older kids, my kids are 14 so they stay up late, and at 11pm all of the MK rides are pretty much just get on, no wait. It's even better at 1am!
I have found the main pools to be real crowded in the afternoon, so we tend to go to the resort quiet pools.
Anyway this is what works for us! I've lived in Florida for 40 years and personally I can't bear the direct sun from 11 to 4pm, it kills me!