What did you guys think of the opening scene (with the security guard and the watch)? It establishes him as a pretty ruthless guy, but is the film better for it? Does it make the ruthlessness of the ending more believable? Or does it rob some of the impact that those future scenes would've had?
I think it works. By having Bloom get confronted, notice the guy's nice watch, hit the guy, and take his watch you establish that he is a ruthless opportunist. By having him wear the watch loosely around his wrist for the bulk of the film, though, it makes him seem like he just took it as a pure opportunity to gain something. He didn't want the watch-it's just an advantage he can have over someone.
I don't think Rick's death was calculated. Bloom had revenge on the brain, and surely had a less violent plan in mind, but when he saw that the guy was still alive, he came up with the idea on the spot. He appears to be a very good unscrupulous improvisor throughout the film. Since he's missing something in his brain, the part that helps connect to other human life, his mind is free to survey all options. It's a bit like Kim Peek being able to read all of the letters of facing book pages at once.