Yes, handicapped people should be given more opportunities to appear in movies. Handicapped people are people too, and they are a normal part of every life for everyone. If you took your idea of reality from movies, you wouldn't really even think handicapped people exist. This is why I think handicapped people should appear more in movies.
Yes, the handicapped people should be asked to participate in the movie scenes which include passive actions. Why shouldn't a handicapped person be a good actor/actress? There are many roles which don't require walking, jumping, running... On the other hand, when a scenario requires a handicapped person, that role should be given to a person with a real handicap, not to be played by physically healthy actors/actresses.
Not only should there be more opportunities for handicapped people to appear in movies, but more people should put handicapped actors in roles that are not specifically written to be handicapped. Handicapped people are people just like everyone else an they are not neccessarily differnt from ordinary people. They have a variety of jobs and roles in real life.
The premise of the question is that there are no opportunities for handicapped people and movies. That is a bad premise. If a movie does not require the use of a handicapped person then simply don't use them. Movie should not be hiring actors, whether handicapped or not, for the sake of just using them. Just make good movies and use the best people.