On the status of Chinese food in Japan, others' experiences might differ, but when I go to a business lunch or dinner with clients or counterparties in Tokyo, at least 50% of the time we end up going to a Chinese restaurant at a Japanese organizer's suggestion. There are a few high-end Chinese restaurants in the Akasaka/Nagatacho area that are known to be regular haunts of Japanese politicians. This makes perfect sense when you consider that most such places have private rooms with big round tables that can easily seat 8-10 people (with communal food and drink in the middle that people can share to add to a cooperative atmosphere).

I get the impression that most Japanese people have deep respect for Chinese history and culture, even if many of them find modern-day China to be completely repulsive.

Re Yokohama's Chinatown: nearly everyone there is from Fujian, based on what I have heard from people who would know.