Peter, I think your site plan / re-imagining of EPCOT was very original - excellent stuff. (I reimagine parks and create new ones via conceptual site plans myself (you can see my work here:
http://www.idealbuildout.blogspot.com/))
I think unifying narrative threads are a major positive and add layers to the theme park experience. Frontierland at DLP is a good example - I believe there is a thread (involving the Ravenswoods) that connects the Manor to Big Thunder and would have extended to the never-built Geyser Mountain. Another example is at DisneySea where crates marked "Hightower" are found near Raging Spirits.
I also think cross-park threads are something that should be explored. Disney is beginning to do this with HKDL's Mystic Manor having a connection to DisneySea's Tower of Terror.
A narrative thread that connects six or seven lands across a Disneyland-style park would be something indeed... I am going to think about that and perhaps try to do incorporate it into a future site plan.