If so, how much, and how does it differ with performance and type of movie?
You don't earn money from being an actor in the Pokestar Studio, but if you talk to the people in the lobby after each movie (watch it first), they will give you items. The more movies you do, the more items you get.
Unfortunately, you do not get paid for acting in movies for Pokestar studios, Even though it may say you made a certain amount of money.