BG, the dog, is not allowed on the furniture. That's mainly because he is so big, plus he lives on a farm. That means he gets nasty smelling stuff on him. I don't want nasty smelling stuff on the furniture.
The cats are a whole different story. There are times I've done all of the choices you listed - move them, make them get down or sit somewhere else myself. Depends on where they are and how badly I want to sit there. They sleep with me. I'll confess I can have trouble falling asleep if there isn't at least one cat in bed with me.
As for asking a guest to go to bed because it was the dog's bedtime.... WTF?!?!? Not something I would ever do. Though I will warn guests they might want to close their bedroom door if they don't want a cat joining them at night.