Nice post, but I don't think this one part is accurate. Being *somewhat* self-contained has been part of the WDW plan from the start. If anyone is interested in the nitty-gritty details of WDW, politics, Reedy Creek, etc. I highly recommend the book Married to the Mouse by Richard Foglesong (note that it is a pretty geeky book for serious policy wonks; that it isn't always complementary to Disney; and that it is kinda pricy. Find it at a library if possible.)
Think about it - how would WDW with all it's development in Orange County back in those days have "partnered" with Kissimmee in Osceola County? Some of the main things RCID deals with are water/power supplies, zoning, building codes, transportation, etc. none of which a city in a neighboring county could help with.