Replying to School project about pro skiing

I've got a project at school about what it's like to be a pro skier. therefore I have a few questions.

How are competitions judged, and what tricks usually winners?
are freeride, slopestyle, halfpipe and railjams judged differently?

Also, why do certain pros get to be in movies? is it all related to the competitions?

If anyone has any other info regarding the life of a pro skier I'd be gratefull.!