I thought this was a thread for people who love Disney/Universal/Florida rather than the whole we went and hated it experience. And it is magical.
Disney's Fast pass is a virtual queue system which you can book in advance. For onsite guests (us) it can be booked 60 days in advance (and the next 10 days of your stay if you stayed that long) or 30 days for off site guest which it sounds like you will be which means you have to log on each day 30 days out. It is a perk of being an onsite guest.
So no, I have never queued for 4 hours for Flight of Passage (where you ride on a Banshee) maybe 20 minutes at most. But it is an incredible ride, you feel like you really are on a Banshee, it breathes beneath you like a real creature would and you ride it around Pandora.
Their Kilimanjaro Safari allows you to see animals with no cages or glass screens, just natural landscaping that means you are close to animals. I was literally 6 feet from a baby rhino just on the path.
So yes for us a once in a life time holiday turned into several visits, I have literally just come back from Universal Studios/Islands of Adventure. The whole Wizarding World of Harry Potter was built by the same people who built the set for the movie, the dragon perched on top of Gringotts Bank breathes fire, the bank is filled with Goblins, the Hogwarts Express transports you from Kings Cross.
And yes it can be hot, but every shop and restaurant is air conditioned as are the rooms and transport systems. So if you get hot you can just walk past an open door for some relief or walk through the shop. There is free ice water at all parks plus water fountains.
TheDibb is a great British website for dipping your toe into the whole visiting Disney World and is obviously filled with people who are enthusiastic about Orlando.