For the most part Actors, regardless how small the role is, are casted because they have a certain look that fits the bill and obviously because they also can act. Most Actors are not very athletic because they really dont have to be. Their face and their ability to act is why they are hired. If an Actor was to get hurt seriously that would delay the movie from getting done which in the end will cost the production company a lot more money if they would have hired a stunt man. Also if you were an actor making millions because you had a pretty face and you can read some lines would you risk all that for a stunt that everybody will think you did anyways? The reasonable answer is no. Its not worth the risk... What Showtime did for FF4 may have looked easy but there is alot that goes on for each gag... Showtime just makes it look easy!!!