I have not seen 'Natural City' but I will endeavor to.
The love story in Bladerunner is excellently handled.
It's very fitting given the theme of the movie that the main character acts largely impotent. He doesn't kill anything but women (shooting them in the back, also), he doesn't solve anything, he gets his ass kicked repeatedly and then the movie ends. I consideration of the themes of the movie will explain to you why these things are good things.
The main character being a replicant is idiotic imo (as it goes directly against the main themes of the film) and that this rumour is perpetuated by Ridley Scott himself for me is more a practical joke on his part than the truth.
A 'big reveal' in movies is usually a very bad 'selling point'. Sixth sense was dross, as any other film from that director. That we're even talking about how Bladerunner is a bad movie based on an example from the Sixth Sense is blowing my mind. Let's see... how can we make "The Fall" a better movie. In the last scene it turns out Hitler was a ROBOT ALL ALONG!!! This explains his lack of compassion!