Also, let's recall that there are degrees of libertarianism. A lot of the early members of this list were anarcho-capitalists -- very articulate ones. There was also a strong bias against debating the basics, so libertarianism became EC (Extropically Correct) and we largely moved on to other things. We probably all agree on a lot of positions characteristic of more mainstream libertarian thought.
I don't share your sanguine hopes for a "rigorous theory of political organization" based on the what I know of the genre.
My challenge to anyone who wants to have a state-based politics consistent with spontaneous order and maximum expansion is to define a theory more optimal than that summarized in _The Machinery of Freedom_.
To minarchists, the main challenge is to define how to contain government.
"Starting with a Constitution and Bill of Rights that reserved to the people all powers not specifically granted to the government, it took less than 150 years to develop a Supreme Court willing to rule that growing food on your own land to feed to your own hogs was interstate commerce and could be regulated by the USDA." -- David D. Friedman, quoted from memory, hopefully not too badly.
To libertarians in general, of course, the main challenge is how to get there from here.
I use this address only when I am away from home. I have reply-to set to firstname.lastname@example.org and I read email sent to that address from here, so please don't use the yahoo address.