You could paint the castle on a wall and have the spires almost be to the top of the wall, then put fireworks above it and continue the fireworks onto the ceiling. To the right, Space Mountain. To the left, Splash Mountain, with BTMRR. An inside scene of IASW, a picture of one of the cars from Dumbo, a scene of Walt somewhere, preferrabily the one of him showing the map of Florida. Show the monorail again, the Seven Seas Lagoon, and ferry boat.
Then to the right of that, create the entrance to EPCOT with a hugh SE in the center. Then show TT in the background, and the Land pavillion, and the monorail track coming around SE, etc. The scene would look like you are looking at EPCOT from slightly above, like from the monorail station.
To the right of that, a huge painting of the Tree of Life, with lots of green, like a forest as a background, but then show scenes from KS - with the "truck" and animals. On the other side of the tree, show the Kwali rapids, a few scenes from the Dinosaur area, etc.
On the last wall, a huge ToT to the right, with a nice scene of Fantasmic! in the center - either with Mickey and the sword and the evil characters, or Mickey with the 'sparklers' as hands, standing on top of the mountain. To the left of that, the NY arch with the tram, show two cross streets (Hollywood and Vine), Kermit, Indiana Jones, etc.
On the ceilings, the skies get darker and meld into darkness with stars.
If you can get a copy of the stature of Walt and Mickey holding hands, that would be cool. Where the entrance of the castle is, if you could cut the carpet and make it like the MK entrance, that would also be cool (IE different colored carpet).