ok, so how did the killer have magical abilities?

how did the killer just magically go back and forth between the movie and the real world? and how did he bring the dead victims from the real world to the movie and the people from the movie to the real world? and at the end they all weren't dead? and how did the projector become magical and be able to operate itself? and how did the film become alive? so many unanswered questions which had to be answered in order for the movie to be good because they are key questions about the movie which have big parts to the movie.