This how my adult only days at Epcot usually look.
Arrive at RD and ride Test Track by utilizing the single rider line. Skip designing your own car.
Ride Mission Space
Ride Universe of Energy 9:35 am
Ride Spaceship Earth with a FPP. around 10:15 am
Ride Nemo and Seas
Ride Living with the Land
Ride Soarin' with a FPP around 11:30 am( I usually skip this, but I think you should see it)
Lunch at Sunshine Seasons around noon
Ride Journey into Imagination
Visit Club Cool to sample sodas
Start with Canada. See O Canada 1 pm
UK - look around, take some pics, see the band if you are so inclined.
France - get a drink, take some pics, see Impressions de France, visit the ice cream shop
Morocco - eat a snack, look around 2 pm
Japan - See Matsuriza if they are playing, visit the shops, marvel at the tiny things that cost $100.

Get a nice break by watching the Voices of Liberty and the American Adventure. Block an hour or time for this.
Visit Italy.
Have dinner somewhere in the WS. 6 pm
Visit Germany. Take pictures of the miniature town, buy something from the Caramel Kuche.
Visit China, see the movie Reflections of China, browse the shops
Visit Norway.
Mexico - get a real Margarita in La Cava, ride the boat ride.
Get a spot for Illuminations at 8:30. Use a FPP or just grab a spot along the water in front of Mexico or Norway.
I hope that helps!