Excellent break down and analysis @andrarchy.

I agree with most of your interpretation, but I don't think John wick lacks free will. Instead, I think John wick represents the writer's and director's ethical alignment in a sense.

What makes John a better person that most of the characters in the movie is that even though he could break the rules, he never does. Well, he does exactly one time. That one time he does, his house is destroyed, which symbolically represents what he cherished. That house, as well as the dog, were earned though his commitment to honor and hard work.

So I think John wick represents a symbolic decision to try to be better. He has a code, a reason for being, and sticks to it. Failure to do so leads to punishment. He's so famous for sticking to it that it's never questioned, and it's the dedication to his willful choice that built all of his success.

There are other themes at work here too, like the innate unfairness of life represented by his wife, or the wanton and chaotic nature of life represented by the death of his dog, but that's for another comment at another time!