I would never do anything that would run counter to my Christian beliefs. More specifically, I would not slap real satanic symbols around my haunt or allow my actors to pretend to be satan worshipers. Nor would I have any scene that depicted a political message (such as democrats/republicans are evil). As for gore, I generally ask my wife and daughter, and if those wimps think I am insane then I take them to other haunters. Sadly, they tend to agree with my wife and daughter.
"To be matter-of-fact about the world is to blunder into fantasy - and dull fantasy at that, as the real world is strange and wonderful." Robert A. Heinlein