overall, i agree with you and have the same questions, as i think most people do. my only point is that NK has advanced their nuclear and missile capacity and technology in recent years.
at this point, i just can't see any possibility of US ground troops going into NK. imo, if Trump were to take action it would be via air and sea, and we should all hope that doesn't happen, mostly for our allies sakes.
The world is not a utopia and there are dangerous people in positions of power. Sometimes the best course of action is going to be dealing with them directly, rather than letting them run rampant. History supports this with lunatics who were allowed to run away with things, who would have been better stopped early on, see Hitler. I think the problem with there being one entity who has taken it upon themselves to be the ones who are going to 'take care of things', is that that nation is subject to the ebbs and flows of whoever is in power. Concentrated decision making on these issues is not a good thing imo and consensus among a larger group would be the better way to proceed.
Before Trump was elected I was most concerned with his use of the military and expected him to start wars and be bombing. He's exceeded my expectations in how quickly he's already there, it' hasn't even been four months. Having an unstable individual who is not qualified leaves the whole world at the whims of likely incompetent leadership and disastrous decision making. Bush Jr. screwed up hugely, but it could be argued that he was surrounded by people competent, albeit complicit - in the disaster of Iraq. Trump is useless and surrounded by mostly useless people. It doesn't bode well for any sort of military action. The man is too emotionally unstable and unintelligent to make coherent and rational decisions. With the people who are advising him similarly unqualified, there is not enough sanity and competent advisement to salvage him from royally screwing up.
I don't think NK is planning to do anything beyond the usual dog and pony show they've run with. If they are actually attacked though, I could then see them launching their nukes at whatever they can reach. It would be a nightmare situation. Provoking them and trying to look tough is stupidity on Trump's part.