Didn't read all the posts after the OP, so this may be a repeat...
My suggestion would be 1 day at each park(you have to see each park!) and leave the 5th day open. After going to all the parks, decide on which you need to still do more at or want to see more at after seeing them the first time. Despite what some folks say, AK is a full day park if you see it all. Many who say it is a 1/2 day park skip some shows or attractions. Yes AK does close earlier than the others, but a possible dinner at Boma at the AKL that night would work in well for you.
The only reason that we ever have stayed at DHS after say 5pm is for Fantasmic!
From your list of 3 options... I would go 1 Epcot, 2MK, 1 DHS, 1 AK. This is provided that you are into the whole MK fantasy thing(which is fine.) However, if you are the type who likes sampling drinks around the world and spending time in each country watching the movie, shows, or attractions... switch the # of days at Epcot and MK.
EDIT: Now that I see you are adding a day, the breakdown of 2 MK, 2 Epcot, 1 DHS and 1 AK seems right. When you get there and see the parks on the first day, you can still change that second day to one of the others if needed. Personally one full day at Epcot is plenty for us... and we usually spend a second day at AK. So I say, still decide on how you want to use those extras days after visiting all the parks the first time. Your money, your time... your call!