It is possible, but not easy, to whip ultra-pasteurized cream, it has to be nearly ice cold, though, and it doesn't stabilize well. You'll find lot of horror stories from people who tried whipping it unsuccessfully.

They often add gums to make UHT cream thicker, which apparently helps how it works when it is cooked but not much in the whipping process.

I've never tried making butter from UHT cream, I don't know if that works.

You cannot make cheese from UHT milk, I"m told.