One of the interesting conclusions one can draw from studies of physics and biology is that it's highly likely that "choice" is really a very complex chemical process, rather than some independent act that a unified person entity performs in complete isolation from their brain and body.
Assuming for the sake of argument that this is completely true, I think we can make significant progress in improving people's ability to "choose" by approaching the problem of detrimental or criminal choices from a biological and physical perspective -- that is, to use a rational, scientific approach to influencing brains and bodies as highly complex, sentient physical objects, rather than a moral, philosophical approach to distributing punishment and reward.
I see this as a false dichotomy. It's the old mind/body duality again. Your assertion about chemicals is not wrong, but you'll run into trouble if you act as if it negates the subjective perspective.
The distribution is already highly skewed anyway.
Note, I don't believe this is deterministic at the individual level. People choose to do crime or to think differently. Nevertheless, at the level of society, the law of large numbers applies.