Not to intrude on your dialogue with others but thought I might share my thoughts. Just as Jefferson was opposed to the Alien and Sedition Acts when he drafted the Kentucky Resolutions (which HCR 6 draws heavily upon), it may be the folks up there are opposed to the Prosperity Partnership of North America agreement.
To be sure, their "cessation" document, having covered most of the bases, doesn't really shed any light on why they got their drawers in a bunch. BUT, if they want to turn NH into the Peoples Republic of New Hampshire, more power to 'em. It is in fact if not in practice, their right.