Some thoughts.
This movie is very politically incorrect when you think about it.
A guy writing a violent book as a revenge scheme against his ex for having an abortion.
I think you're even supposed to cheer at that last scene.
There's a specific anti-Republican line at one point - and even that kind of thing is no-no in movies/shows these days. I get the feeling that Tom Ford put that in there in an attempt to throw you off the scent? However, you could read it as another jab at Amy's character.
This is also one of the very rare movies/shows I've seen where an actress has at least 10 years on her male interest and it's not a plot point.