I agree with much of this, but the idea that the LP is in danger of becoming “a third party that looks identical to the Establishment party” is such a tired canard that its evisceration is kept on file here: http://libertarianmajority.net/is-non-anarchism-just-republican-lite
The same sentence also seems to spread the Wasted Vote mind-virus, which is by far the biggest obstacle confronting the LP. One antidote for this meme is at http://knowinghumans.net/2008/04/vote-by-your-principles-not-by-habit.html.
I have no problem with welcoming anarchists. My problem is with privileging their school of libertarianism, e.g. by giving it effective veto power regarding the platform. For details, see http://libertarianintelligence.com/2008/05/restore74-with-denver-accord.html.
I reject the apparent assumption in the essay that anarchism is the purest or most principled form of libertarianism. Not by this metric it ain’t: http://libertarianmajority.net/more-libertarian-than-thou.
Nevertheless, I see plenty of common ground here, and it sounds to me like Alex would subscribe to the draft St. Louis Accord.