My husband and I will be in Egypt in November for a short period of time. We would like to see/experience Abu Simbel...are we best to book flights via Air Egypt before we leave, or can we book a tour from a hotel in Luxor when there?

You can do it either way. Winter is a high travel season though, so flight tickets might be hard to come by at the last minute.

Flights are hard to come by now!
The overnight sleeper train arrives in Aswan at 7:15...is it too much of a rush to try and get from the train station in Aswan to the airport for a 9:50 flight to Abu?

<<<The overnight sleeper train arrives in Aswan at 7:15>>>

Yes, but mostly because this isn't Switzerland and you can't count on the sleeper train actually arriving on time! We were three hours late -- apparently sat on the tracks for some time during the night (I was sound asleep) -- didn't arrive at Aswan until mid-morning.

I read about that happening.
What would your suggestion be? I have 3 days in the Luxor area..

You can fly down from Luxor. Make your reservations on line at www.egyptair.com

Or you can do it as I did drive across the desert. It is however a very long trip with not much to see sight wise. Doing it that way takes up your day and you of course don't always get there to see the sunrise I missed that,but it did have the advantage of on arrival having not anyone else there but the vendors and the people in the cafe. Bliss for me is a uncrowded site that one can explore and soak up.