That wasn't nail polish she was using on her teeth, it was stage makeup intended for use on teeth. Like these: https://www.stagemakeuponli…

I think they didn't really murder that guy. Maybe his wife thinks they did, but it seems too early in the show for them to be murdering people.

I mean, we're talking about fanfiction of a TV show based on a movie based on a book. And it was awesome. Just because a thing is based on a different thing doesn't mean it's automatically terrible.