I was there the first week of October and it was BEAUTIFUL! Would I go again that time of year?
YES 100% the weather was sunny and warm during the day with no possiblity of rain

. You can wear shorts, capris, t shirts and tank tops with sandles and you could go swimming if you wanted. But in the morning its a bit nippy but warms up quickly, but come the evening you need to put on some pants and a jacket. One thing that I loved was the fact that it was really warm but it wasnt like HOT HOT STICKY summer heat. It was just perfect.
As for the rides most of them should be open. Its not like earlier in the year where a large majority seem to be closed. All attractions and shows (Fantasmic, Fireworks, Aladdin, Parade of Dreams, etc) seemed to be open except for the matterhorn and autopia, and the Electrical Parade. Granted watch the calender cause the fireworks and fanstamic is only on weekends during this time.
The lineups were fantasmic

haha! Buzz 5 Minutes, Pirates 5-10 minutes, Space Mountain 10 Minutes, Splash 15 - 20 min, Haunted Mansion 20-25min due to the holiday overlay etc.
The only downfalls I found during this time was that the park does close a bit earlier then usual, like around 8pm, but that just give you time to wander DTD or kick around your hotel pool for awhile. Also like it was mentioned above, if you have problems as "Gay Days" is going on during that time, usually around the 7-9th then I would take that into consideration.