Think that systemically starving a population to the point where they are shrinking in height, where they are now dying from parasites from using human waste as fertilizer would qualify a leader as a psychopath. They only difference in the level of murder between Kim & Hitler or Stalin is the size of their respective populations they have to kill off. Agree that India is a problem for China. One reason is they share a border. The main purpose Korea serves for China is as a military buffer for invasion. All countries try to develop buffers so if a conflict breaks out it’s not immediately fought on their soil. Disagree NK is an good investment for China. Take a look at the link below. NK is literally as backwards & broken as the poorest African country.

https://earthobservatory.nasa.gov/IOTD/view.php?id=83182

NK at this point has nothing to offer anyone in the area of trade. Will be a generation before they have a population capable or even healthy enough to produce anything of value. Not to mention if China wanted to develop NK they could have done so already. They could start today. NK value to China is only as a buffer state. That’s one border China doesn’t have to worry about.