I have a LOT of thoughts about Epcot as it is the park that I basically grew up with since it first opened...my father worked on the computer systems at that time (and could be seen in the Astuter Computer Revue/Backstage Magic show).
Anyway, I think with some creative minds and investment from some of the top technology companies, Epcot could be a "cool" place and still feature future technology.
Ironically, at the very time that geeks and technical people were becoming more prominent and popular in our daily lives, Epcot began moving away from that.
Anyway, here is what I would do:
Keep WS and add some minor things, I think we're in agreement on that.
FUTURE WORLD, however could use some radical re-designs.
Pretty much the only attractions that are relatively fine are Test Track and Spaceship Earth, the rest could use some changes.
I would take the spinning portion entirely out of Mission:Space....let me explain. I've heard they're running most of the simulators on the GREEN, non-spinning side now, and if they don't spin...the whole idea of a ride you actually interact with comes into play. The scenes and experiences can change depending on your input. It couldn't happen with the spinning ones because the other centrifuge portions relied on all experiences being the same...movement-wise.
Right now, Mission:Space relies heavily on buttons and controls that are basically FAKE and don't affect anything. It's seriously bad for that reason IMO.
I would fix the ending of Spaceship Earth and change the narrator...let's get Patrick Stewart or Neil Degrasse Tyson and a better script and stop trying to pander to little kids all the time.
Innoventions....let's make the entire central plaza area under one clear geodesic dome (yes I know there's already 3 other Geodesic structures in Epcot...why not 1 more) so it's more weatherproof.
Open up Innoventions to the central dome area and make it brighter and more inviting. Communicore was always said to be like the "Main Street" of Epcot, but ironically most people can pass right by and never actually go inside.
I think Epcot should basically take on its own identity outside of the standard Disney parks and advertise itself to the Science/Discovery channel types...Open a large area where the old Wonders of Life pavilion is...or even replace the whole building...have TED Talks presented there, have Battlebots competitions or other robotics competitions that are open to the public and advertised more....let the guests build their robots and compete while they're in the park for an hour.
Let kids share their ideas for the future, similar to the poll taken about the person of the century.
Bring back the educational field trips for local schools like we had in the 80's and have "Dine with a scientist" or similar types of experiences.
Bring in more technology shows which don't rely on special contracts that have been like a boat anchor for Epcot in allowing other vendors. Bring in the brightest minds to discuss attractions for the future, the ones who are actually going out and building the future now.
This is just some of the ideas I have for this shell of a park. Sometimes I wish another company would just buy it out from Disney and license everything, then build it up.