Can a guest at a hotel file a complaint and demand for money or change of room after 4.5 hours of being in it?
I don't know the legalities unless the room is uninhabitable for some reason but I would think that the hotel would want to keep you happy if there is another room available that is more to your liking.
yes if the situation warrants it
Sure you can ... doesn't mean you'll get another room, but you can try.
Rarely. You would have to have a GOOD reason, like there was raw sewage coming through the walls, unbelievable noise from elsewhere, or fleas or pests.