Is it possible to use a mobility scooter on the streets of the above cities and get into many of the public buildings, museums and theatres. I can walk short distances and one flight of stairs but need the scooter to tour around a building or wander through the main parts of town. Thank you.
Do you mean a wheelchair that you press buttons or use a klutch to manuever around, or do you mean a 2-handled half-cart on wheels that you push because it is sturdier than a cane?
I think you'll find Vienna would be quite well taken care of, but I'm not so sure about Budapest or Prague as these are both in slightly less developed countries. It's hard to say, although I've been to those places, it is always different when you can walk around freely. There are a lot of old buildings in these places though, so often they won't have elevators, etc.. There are also lots of cobbled streets, which I'm assuming would be a hindrance.
Prague is really cobbled so I wouldn't advice to visit