Anthony, the LP can't be "solidly libertarian on everything", since there is a non-trivial array of issues on which the LP has never taken a position. Many of them are in the list at http://libertarianmajority.net/free-variables-in-libertarian-theory.
The LP's candidates should indeed "try to be as principled as possible", but I don't take that as meaning that the LP's candidates should try to be as anarcholibertarian as possible. That is, I think Caplan's test measures anarcholibertarian purity rather than libertarian purity. (The last question is a dead giveaway, when it asks if you would call yourself an anarcho-capitalist.)
I personally think LP candidates should try to be as EcoLibertarian as possible (see http://ecolibertarian.org/manifesto), but I wouldn't have the Party's official texts enforce that advice.
William, I don't agree that "libertarians and paleoconservatives [must] combine forces behind a common platform". In fact, I think that would be counterproductive, as it would undercut our primary message that a Libertarian platform is neither Left nor Right, and would strengthen the insidious perception that libertarianism is just a fringe variant of conservatism. I would agree that we should embrace decentralism and constitutionalism as a _strategy_ for increasing Liberty, but we need to make it very clear how the LP is different from the Constitution Party.
We are the only party in America that wants to legislate neither personal morality nor economic equality, and thus is neither Right nor Left.
That's the message we need to hammer home to the American electorate a few billion more times. Our message should not be "Vote Libertarian, we're sort of conservative" or "Vote Libertarian, we're anti-establishment". (Anarchist/radical libertarians love the latter message, because it has a coded meaning to them that is lost on 99.99% of the public, but the resonance of its prima facie meaning gives them the warm fuzzy feeling that their beloved anarchism meme is spreading.)
