We will have to disagree over the comparison between the mafia and the Xeer system. Just to clarify, when I mentioned banishment, I meant banishment of the clan itself and not the individual. This does not happen with the mafia and police. I would think of the police as external aggressors on mafia clans.
I agree the social networks in the west are far more complex, but I think the bonds are weaker than other parts of the world, which has resulted in the right kind of individualism. I'm not sure if it's common conscience or something to do with "thinking ahead" that makes the west work. That European genetics results in low time preference, especially compared to sub-saharan, is apparently well known. If this is true, then as I suggested, prisoner's dilemmas tend to turn into assurance games (more so than for players with high time preference). Here's the math.
We will have to disagree over polycentric law as well. I'd certainly hope that you give it more thought and look at it from an economic/analytic perspective. I agree that polycentric law (coupled with libertarianism/NAP) won't necessarily help kill the parasite. But the ethics you emphasize upon can be worked in to a (non-libertarian) polycentric system. I just don't think there's any economic validity to a monopolistic system. Nor are Curt's normative writings scientifically grounded, if you were considering using that as a basis for society.
Also, you might be interested in this book which is still on my reading list. /u/properal likely has a lot to say for it.