So who are we to play god and decide who deserves to rule and who doesn't?
NK under the Kims' is a brutal and often barbaric place (and believe me, I have heard first hand accounts of brutal acts beyond even what is mentioned by the western media), but the same can be said of many other places today like Saudi Arabia, Egypt, Myanmar and many others.
Even places like the UK, France, America and China had pretty disgusting phases in their history where horrific things (even by the relative standards of the time) were normalised.
So, either you support a new crusade to unite the entire world under one set of rules and standards, or you are hypocritical for suggesting some regimes need to be toppled, yet others that are just as bad should get a pass because they are useful to you.
Yes, the Kim is awful and the world would be a better place without him in charge, but I dare say most Americans will at least secretly agree the same sentiments apply to Trump. And the cost of trying to remove Kim militarily is unthinkable, which is precisely why he is hell bent on getting nukes and ICBMs, to make that cost even higher.
For him, nothing matters as much as his survival, which is why he would happily see millions of his countrymen starve to death if that is what it takes for him to get a reliable nuclear second strike capability as the ultimate deterrence against regime change.
As distasteful as China find him, China is still bound by treaty and self interest to protect NK from foreign annexation or destruction, because no matter how bad NK is under Kim, it will be a thousand times worse for everyone in the region to have a Libya or Syria situation develop in NK.
Beijing is already within range of NK nuclear missiles, but you don't see the Chinese loosing it over the fact because they know that Kim is not crazy as the western media loves to caricature him.
He is brutal, heartless and above all, incredibly selfish and self serving. Which is why he will not launch a nuclear first strike, because that is the only scenario where he dies screaming in a fireball despite having his precious nukes and ICBMs.
There's a big flaw in your argument about non-interference.
Remember that China does play God by subsidising NK in the first place, rather than just operating on a commercial basis in many other places.
If China was really neutral, then:
1. North Korea would already be bankrupt and its military/industrial capacity crippled. That is simply the result of its Juche ideology and having to pay a lot money for Chinese imports on commercial terms. Then there are the preferential items and technology that North Korea received from China, which it cannot obtain from anyone else in the world.
or
2. North Korea would have to abandon its Juche ideology, which means means real reforms at a minimum and definitely much more interaction with the outside world.
I also think that there is no way that North Korea can descend into a Libya/Syria type situation. There simply aren't the divisions in North Korea society that exist in Libya/Syria, which have caused them to fragment. Nor would North Korea be left alone and neglected for years like Libya/Syria. At a minimum, South Korea and China would step in to stop that happening, and they both have the capacity and political will to either stabilise or destabilise NK.
Otherwise I think the rest of your post is accurate.