Not really. They only act that way from time to time.
They love that The West is getting tweeked.
It doesn't cost them a thing financially or politically.
When they really want a change...there will be one.
Yes...while...keeping CHINA from having to share that border with a Western prosperous nation like South Korea.
Even the peasants in CHINA feel rich when compared to the North Koreans.
If CHINA shared a border with South Korea, even most of the Chinese rich would feel poor in comparison.
The ruling elite of CHINA fear an unrestricted interaction of their population with a prosperous Western nation more than just about anything.
It would, as they know, inevitably result in the downfall of the current political structure in CHINA.
You are absolutely spot on there. I dont doubt for a second that China love the fact that North Korea is a real thorn in the side for the West. They buzz off it definitely. And yep, keeping the people blind is good for China

When I was growing up in Ceausescus Romania, we we told day and night how "fortunate" we were, and how The West was impoverished, and we were the chosen few. And how shortages in the shops were the fault of The West and their policies.