This is a long one you asked for it
I recall Great Britain was supposed to have a Music Hall of the late 19th century, and Japan or Italy was supposed to get a boat ride.
For that several years it's always been very funny reading all the posts by people saying "Disney always builds their theme parks small and then fills them out over time". This is, of course, a complete and utter corporate lie and EPCOT Center is a shinning example of how the "old" Disney did things right. Not only was EPCOT Center a huge park when it opened, there were already several expansions in the final stages of design already in the works on October 1, 1982.
I've already written about the 'Meet the World' and mountain rides for the Japan pavilion. The Germany pavilion was supposed to get a Rhine River cruise. In this attraction you'd float past scenes depicting the various myths and legends associated with the Rhine, see lots happy Germans stomping grapes for wine, and other "picturesque" scenes of the country side. The show building for the attraction was built, but the ride itself ran into sponsor trouble. The early 1980's was a "hot" period in the Cold War and Germany was stirred up with more than a little anti-American sentiment (anyone remember the protests over the Pershing missiles?). Disney decided to postpone the ride until they could find good corporate backing. There were also rumors that Disney management at the time really wasn't comfortable with the idea of a brewery sponsoring a Disney attraction. With the automotive sponsorship already taken by General Motors, there weren't a lot of other well-known German companies that need that type of expensive entertainment.
A concept for the England pavilion was for a dinner theater or a variety house (think vaudeville) from the Victorian era that offered a continuous show. I also recall a vague rumor about a "mini" Tower of London that would have housed a traveling collection of crown jewels. English vacationers make a big percentage of WDW's foreign guests; the trick was to find something that would appeal to them as well as to the American guests as well.
People also forget how big a deal the China pavilion was when it opened (again, the Cold War). There were very, very few American tourists to China at the time and most people were still trying to get used to saying "Bejing" instead of "Peking". The CircleVision film Disney created was one of the toughest films the studio ever created. You could hear people associated with the film talk about being surrounded by armed guards and how no Americans were allowed in the helicopters during the aerial photography (which was done by the People's Army). Disney was the first western film crew ever to have shot in some of the locations. There's been a lot of history in the last 25 years.
Over in FutureWorld, four additional pavilions were planned in addition to the ones on opening day. 'Horizons' (which was once called 'Century 3') had already had its groundbreaking. Shortly after that was to follow 'The Living Seas'. In addition to the main tank and Seabase Alpha, the pavilion was also going to have a 15 minute ride through various scenes showing different ocean locations, different marine life, and the ocean's potential for energy and mining. The show would have begun in a theater surrounded by a forty-foot waterfall and a thirty-foot high auto-animatronic figure of the god Poseidon.
A health pavilion was also in the works featuring an attraction called 'The Incredible Journey Within'. It would have been another omnimover type ride, a tour through the human body. This ride was originally planned to be ready for opening day and construction had started on some of the show sets. Sometime around this point WED began feel unsure about the ride and called for a break. Some people thought the story was too clinical and dry. There were technical problems with some of the effects (like how do you get a sixty foot heart to beat realistically). Some people didn't like the "ick" factor of giant sized blood vessels and organs. And no one could ever really figure out good places to enter and leave the body (how's
that for an ick factor). The pavilion was pushed back into "Phase 2" while those issues were worked out.
Lastly there was the Space pavilion. This one had a hundred ideas all of them expensive. Disney decided this was mostly likely to be the most popular pavilion in EPCOT Center and they wanted to get it right. With all of the company's resources stretched beyond their breaking point, they decided to wait until later this even start it.
So why did 'The Living Seas' get the pitiful SeaCabs instead of the gigantic God of the Sea?
Michael Eisner took over the Disney just two years after EPCOT Center opened. The management that designed and developed to park was thrown out of the company. Eisner
well, let's just say he had issues with EPCOT. Eisner had been running Paramount Studios and only knew about the movie business. He knew nothing about amusement park, and liked them even less.
Eisner came in with bold plans to make Disney Studios a major player in Hollywood and make twenty or more movies a year. Only he found out that Disney had just sunk all their money into this place in Florida for tourists to look at a knock-off of the Eiffel Tower (the grapevine story almost certainly wrong is that Eisner was supposed to have blurted out 'why don't they just go to France!? I go every year!").
Even more appalling was the length of time Disney was willing to wait to get its money back. EPCOT Center had been built with the ling term in mind twenty, thrity, forty years. Eisner, from his movie background, expected to see the returns on his money instantly. You put fifty million into a movie, you get it all back and profit (hopefully) in the film's ten week theatrical release.
Lastly, Eisner just didn't get EPCOT. Another grapevine rumor was that Eisner had never been to any Disney park ever until he was offered the job as CEO. Eisner is not one to "mingle with the masses" at the best of times, and he is infamous for how high he believes his tastes are (foreshadowing all the problems with California Adventure). Eisner could see where factory tours and places like Williamsburg
might be interesting, but EPCOT was just so, so, so middle class. It had a fake Venice and everything.
So Eisner began to work. He put an end to all future capital investments in EPCOT Center. He ripped out whatever he could that was already in the works. The African Pavilion (for which all the shows had already been filmed), gone. The Living Seas ride-through (already under construction), gone. Spain, gone. Refurbishment of Communicore, gone. Space, gone. Monorail expansion to the Disney Village, gone.
Then Eisner turned around and tried to find someone to buy the place. The concept was someone would purchase all of EPCOT Center. Every ride, every building, every tree. Disney would lease back the park and operate it. The buyer would collect annual rents and fees, Disney would have a whole lot of cash up front to spend on making movies.
Fortunately better minds prevailed. They focused on creating limited partnerships to fund the initial waves of movies. Disney would get the cash that way and trade off some of the profits on the back end. That's the "Silver Screen" credits you see at the beginning of the "early Eisner" movies like
Three Men and a Baby.
While EPCOT was saved from the garage sale, Eisner never really warmed up to the place. The closet he got was when Met Life agreed to pay for 'The Wonders of Life'. Eisner leapt at the chance to make a "good" amusement park ride. He brought in all the big Hollywood talent the gang from Saturday Night Live for 'Cranium Command', the director from the (then) uber-hip 'Moonlighting' TV show to teach little kiddies where babies came from, and he even got Mr. Spock himself to direct 'Body Wars'!! Eisner was sure the public was going to love it!!!
And to this day he has not forgiven you for the ho-hum reception you gave his brilliant pavilion.