Personally I think you are asking too much of yourselves with a visit to MK and Epcot over your first 2 full days.
Some people think that the Disney experience is all about MK and go on either the day they arrive or the first full day. Personally we much prefer to go to a less stressful park on the first day, MGM Studios, Sea World or Universal Studios for example.
Don't get theme parked out so quickly, it's easily done but you can get over it by spreading your days across your holiday.
Also, I don't think you should be looking at Epcot as a chore, if you really don't fancy it then don't go. You will however miss out on 3 great thrill rides (Soarin, Test Track, Mission Space) and a chance to experience Walt's vision for the future.
The good thing also about Epcot is then with both Spaceship Earth (if open) and Universe of Energy, there is a chance of some air conditioned shut eyes for a few minutes....although of course if this is your first trip you will be wanting to enjoy these rides for different reasons to me!!!
Still a shame they got rid of Food Rocks though!!!!
Enjoy anyway.