A little bit the opposite direction of most of your foreign policy reads. I applaud you for the variety. Fairly simplistic evaluation, but I think he's mostly spot on. Only area I disagree with him is at the end where he implies we should be removing troops from South Korea. To use his terms, I think that would amount to capitulation from us without gaining any significant concessions on NK's part to this point. I hope we achieve a position where we can draw down our standing troops from the region (not just SK, but Japan as well), but I don't believe we are there today.
I do agree that our president oversells his wins. That said, its patently false to imply that nothing's been accomplished. NK has not executed a nuclear weapon test or a long-range missile test since the summits started, and the only test at all was a short-range rocket test which very coincidentally occurred the same week the US/China trade deal fell through. The US in return has ceased the war game exercises with South Korea. Diplomacy at this level (and extreme) is going to be done in small steps, and these concessions from both sides reflect that.
The one thing that is worth noting however (and this scares me most about NK) is the fact that they are still China's lapdog. I believe the SRM test was driven by China and not NK (based on timing) and thus indicates that no amount of diplomacy with NK will overcome a 'cold war' relationship with China.