[ZenGum]

I agree that whatever Chinese culture was like before, the Mao era made it much worse. That sort of prolonged internal terror leaves a society collectively traumatized.
And I guess that it will take a very long time to recover the socio-cultural strength that was smashed in the cultural revolution. Social cohesion is an organic thing that grows slowly and can be ruined quickly. Like a tree that takes thirty years to grow and can be cut down in one day.

On the Japan/China relationship, the Japanese side is one of at least disdain and at times contempt.
Japanese culture greatly values hygiene and politeness. Hence the Japanese view of China is one of extreme dirtiness and rudeness.
The Japanese press focuses on the involvement of Chinese (or any foreigners) in any crime. So Japanese people also perceive Chinese as being more likely to be criminals.
Meanwhile Japan is still denying war crimes like the massacre at Nanking and the forced prostitution (the "comfort women" - a phrase I hate as much as "ethnic cleansing") and glossing over how Japanese forces came to be in China in the first place.
Good news for worried westerners, then, is that there is very little chance of these countries uniting against the west.