I think that is an excellent decision, feeding F/T! Another bonus to feeding F/T is that if he doesn't strike the rar right away you can try leaving it in the enclosure over night.
Definitely never put a frozen rat in the microwave, you don't want blown up rat all over in there.;) I personally just take the rats and put them in as hot water as I can from the tap and let it sit for 10 minutes or so, my snakes all have excellent feeding responses and don't mind if it is cool, but if one of them is finding the rat too cool I will refill the jug with hot water again. Some people have issues with their rats bursting open when their snakes constrict the rat with the method I use. I never have.
I would definitely wait until he's had a meal before handling him.
My snakes sometimes will spend days and days on the cool side and then go back to the hot side for a few days. If your temps are accurate and where they should be, he will go where he feels the need to be.
Never go past 95/96, likely your snake would find this too warm, but if temps fluctuate then I would not allow it to go above that.