So I don't think I would call this a comedy or even a dark comedy- I think its more along the lines of a horror movie. I feel like the people calling the main character's con unrealistic are unfamiliar with the ward/guardian/conservator system in the US.
The main character is totally repulsive.
Lots of the stuff that happens is unrealistic, but it was still an interesting movie & the con is quite terrifying. I'm glad I didn't read these reviews before I watched the movie, as some of these reviewers are real jerks- just because you don't like a movie doesn't mean you need to go posting spoilers of the whole thing to ruin it for everyone else.