If the movie's intention was to make people feel traumatic, feel the helplessness, the sadness and pain of the girl and her family, then the movie has done its bit marvelously. Every actor made you experience every bit of the pain. Very well acted.
However, for a close knit family, it might be a painful experience to be there for 2 hours. Especially for parents!
There is nothing related to superstition. Its a story of an unfortunate encounter with an evil force.