I like it! And on Day 5, depending where you head, that will determine where you are on days 6 and 7. I think you'll only need one FULL day at AK, especially since you probably won't be riding Everest or Dinosaur. More shows and just wandering around AK, so you should be good. And of course you could always pop back for a couple hours later in the week.
I would plan 1 FULL day at Epcot, at least, and at least a day and a half at MK since your kids are so young. 1 day at AK, and 1 day at DHS (lots of shows here so you may end up a day and a half with young children). That said, it looks like only 5 full days, so you've got plenty of time! Just save day 6 and 7 for extras.