It remains to be seen whether his macho rhetoric against North Korea was any more damaging than previous sanctions have been.
Tbh, it's impossible to say what effect he has had on NK relations. On the surface, he seems to have made them more paranoid and uncontrollable, but they weren't going to stop their buildup of nuclear arsenal anyway. I think Kim Jong-Un has the same sense of self preservation as any world leader, so his bluster may have concealed a genuine fear that Trump would turn his country into a crater. On that particular issue, we'll never really know until a nuke is dropped which, hopefully, is never.
With regards to damage he's done, it mostly pertains to the damage of America's international image, which is big or small depending on who you ask. I would rank the firing of Comey, some of his disastrous appointments, his hurricane relief efforts (better than Bush though!) and the emboldening of the fascist right as damaging. I don't think he's been the complete force of destruction he's painted as, just that he should be called on the things he gets wrong regardless of whether he's your man or not.
I'll just repost my initial reasoning for wanting the lad in office, and I think some of it has even held true. Particularly regarding the fact that he is completely hamstrung by both parties and seeing the Democrats in an utter state of disarray that looks to be leading to some proper introspection. Maybe the Republicans will follow suit. But while he's here, he needs to be held to a much higher standard than his supporters seem capable of imposing
They've been talking about change for how long now? It can't happen. Since the 90's it's been Bush, Clinton, Clinton, Bush, Bush, Obama, Obama (and make no mistake, that was supposed to be Clinton) and now they're setting it "right" with another Clinton. Sanders' problem wasn't a lack of mobilization, it was that the supposedly impartial DNC funded and favoured Hillary's campaign and bought off delegates. Gradual change won't happen while both parties control the game. Ron Paul mobilized grassroots support 4 years ago in the Republican primaries and they just changed the rules halfway through to prevent him from troubling the nomination (ironically the same rules which would go on to sweep Trump to victory 4 years later). Make no mistake, they won't let it happen again.
With regards to Trump, I think people severely overestimate the damage he could do. I reckon international relations would be strained, but I think the long term upshot of a Trump presidency outweighs the negatives. He'd be the first president that would have absolutely no support among the houses or either party. Obama had the support of the Democrats and he could barely do a thing. As near as I can tell, Trump would be almost completely ineffective.
What's important is the message. The two main parties have a monopoly on the political dialogue and will move mountains to ensure the likes of Sanders can't threaten that. Protests haven't worked. Decades of promises have yielded nothing. This is the American electorate's chance to make a radical statement that they may not be able to ignore. Start giving American people an actual choice. Stop sending out compromised puppets with no other purpose other than to prop up a blatantly ugly system.
It used to be the case that people were willing to undergo necessary hardships to express their point. Civil and women's rights weren't won by the middle class sitting back and fearing for their comfortable way of life. It's baffling to me that people, at once, cry about the severe inequality in the American political system, and then intend to go out and vote for Hillary.
On almost every occasion when it matters. It's ludicrously transparent but people are being cowed into believing Hillary is their only choice by a political structure and media who are basically cooperating. If I lived in the US, I would be absolutely fed up with the illusion of choice I was presented with and take this golden opportunity to force them into a rethink. It might not work, but it's better than being bent over for the bajillionth time, pretending you like it and telling them you'll see them in 4 years time