Fastpasses in Sept, no way jose'! That week is our favorite time to go. The only wait we have ever had was about 15 min for Star Tours and that was only b/c we watched Indy and us and everyone else headed for ST when it was over!
We have walked on everything in Sept with waits of no more than 10 min, included Splash and Space Mountatins, BTMRR, ToT, RnR, Mission Space, and Test Track. Alot of FP machines for smaller attractions have been covered up most if not all the time we were there in Sept. We have not been in Sept with Soarin' open, so you may want to check the lines for FP options on that one and of course EE.