Buchanan has shot his credibility as a politician, but often makes good points and raises important questions. The GOP is eventually going to regret its embrace of the neocons and move to a more main street, less globalist, less interventionist point of view, though. But it won't happen if the alternative to globalism is perceived as being tribalism or racialism.
Fleming is far too much of an armchair emotionalist. I can't consider him any sort of serious thinker or even a good writer. So much of his writing boils down to "I don't like," and some of the things he does like, sociobiology for example, have real problems for many. I don't think he has much understanding of history beyond a good guys vs. bad guys approach.
Dittos for Rockwell who also flirts too much with anarchy. So much of what gets put up on his website can't be taken seriously. The eternal "I hate the state/government is evil" refrain is more apt to turn people off than to attract them. He comes across as very much a Johnny One-Note.
I regard this LOTS/SIP nonsense more as a damning rather than a redeeming feature. An intriguing idea about American history gets pounded into a dry, narrow, spectacularly wrong-headed orthodoxy. Secession becomes a cure all, and the Confederacy the great alibi of American history.
Liberty Magazine has much in common with the paleolibs without falling into their grosser errors. There's an interesting article in the March issue contrasting Mises with Rothbard and Rockwell and questioning what they've done with his work.