None of the characters are terribly well developed, but the main character is evidently a good husband trying to get justice for his slain wife. His good intentions don't prevent a downbeat fate. His aged, invalid father has married repeatedly, lately settling (apparently) for much younger bride.
Victims of the ghost have their tongues torn out -- though the gory deed happens in "supernatural" bursts of speed, so (usually) the worst we see are quick glimpses of the ghastly corpses that result. One victim vomits up blood. Others fall from great heights through floorboards. There is a quick-cut of a lynch mob about to kill and mutilate a woman with a razor. Dead bodies include children.
Some very mild innuendo between young marrieds.
"Hell," "ass," and the very beginning of an F-word.
None, except a quick inside-joke reference to the Saw movies.