These are enduring questions. Nobody can give a complete answer, full stop. They will stimulate intellect, provoke interest, engage investigation. It is mysterious, even inscrutible. These are but a few citations of the mysteries and riddles of Chinese culture, the tip of an iceberg.
Chinese culture is rich and profound.
It has the richest historical records. Chinese have been most historically-minded. Perhaps, China has more historical records than the whole world put together. This guess will not be far from truth. She is not the home of Buddhism, but she boasts of the richest Buddhist scriptures.