What I found most interesting about the essay was Colin's spot-on description of the character as being fundamentally passive, despite his kit and kibble. Deadshot IS passive. He rarely acts, preferring to react, and even then, only in the most literal fashion. It's an interesting trait in a super-villain, especially one that's an assassin by trade.
In a sense, Deadshot kills without hesitation because it's the absolute least amount of interaction he can engage in, in a social sense, without simply shutting down into a comatose state. He's effectively disabling the social machinery of any given confrontation by cutting to the quick and eliminating the other points of view. Even more disturbing, he seems to do it not out of a desire to win/survive/prove his reality but out of simple boredom.
Conflict, in all its forms, seems tedious to him. Thus, he seeks to end any engagement (be it an argument or otherwise) in the quickest manner possible, with the least amount of interaction. In a way, Deadshot is the mirror opposite of another Bat-alumni, the Joker. The latter sees interaction as art...he's all about social engagement, whether via murder, fear or humour, talking incessantly at his opponents, forcing them to engage with him on multiple levels. Deadshot, in contrast, is nullification personified-a machine, propelled forward on internal mechanisms which are completely isolated from the rest of reality.
Of course, when circumstances conspire otherwise, forcing him into some form of pre-emptive action, Deadshot becomes even more lethal (as Colin noted in his essay), if such a thing is possible. Yet, in acting, he loses efficiency, often causing situations to become even more chaotic because he simply can't function correctly when he's the one directing traffic. Eventually, his passivity reasserts itself, and with it his inhumanity, often leading to an abrupt, unhappy ending for someone.
Like I said, thought provoking.