One character points a rifle directly at another for some time clearly threatening to shot him; this could be frightening/intense for younger viewers.
The scene where a deer dies is quite intense as one character experiences the pain that the deer is going through.
Some of the bullying scenes are quite intense - one includes stripping the main character (his full body is then seen from behind a few times). There is a sense of the main character being under threat throughout a lot of the movie.
Some of the scenes where Powder enlightens others to the pain they're causing can be intense.