James Lance played his part well

Agreed.

I felt like the movie had a difficult time finding a consistent tone. Some parts of the movie were delightfully campy (as in all of the scenes with the brother), while other parts were pretty horrifying (like the rape/forced pregnancy/drugging/etc).

I would have rather watched a whole movie with a tone that matched Lance's performance. The imprisonment/rape pretty much killed my interest in the movie--just too nasty and cruel.