Okay, that jives with most of what I've suspected. So, the way I see it....
Building 1 probably will stay as it is needed for park functioning and trying to put its use somewhere else would be very expensive and disruptive.
#2 & 3 are needed for the park somewhere but not specifically at those locations. So, developing a new building for those use and using the footprints for guest purposes is realistic. I suggested, for example, putting a new building(s) on the far side of World Drive and having a walkway over the road to get into the park would be a reasonable solution. Also, could consider putting a building south of GE/Echo lake in the current parking between the park and the Starcruiser (I don't like this as much as it might limit any footprint if/when the Echo Lake area is repurposed for future expansion).
#4 & 5 sound like things that don't have to be at the park. Sure, could be kept there if needed with anything else that gets moved, but this just speaks to getting some office space elsewhere in the general vicinity.
If you move most/all of this backstage stuff, you can also remove the parking deck (south of #3/4) as then parking could be placed next to wherever the new buildings are.
If you free up #2/3/4/5 and the parking deck that is a ton of space that could be used to expand the park. I'm not saying they need to use all of it, but it should provide flexibility put in a great expansion and not be that constrained by the footprint.