There is a series of 6 books called "History of Imperial China" that are all written by eminent historians in the field. Each book covers 1 or 2 dynasties. I would recommend these books more if you have a particular interest in a few specific dynasties.
I do not know of many general histories of China, but if you need recommendations for books on more specific topics (especially Late Imperial China and Modern China) let me know!
There is a 6-part book series written all by experts in the field of Chinee history on imperial China. No single book is too too long, but they go into more detail on the individual dynasties than general sweeping histories.
For your "secondly" there are a great series of 6 books called "History of Imperial China" published by Harvard in which top historians take anywhere from 1-2 dynasties at a time and write about them, starting from the Qin and Han and ending with the Qing. I also hear that the "Story of China" by Michael Wood is very good and readable as well. It is much more akin to narrative history and leaves out most of the academic jargon.
For your "lastly", one of the most powerful and important pieces of literature regarding post ww2 Japan is "Embracing Defeat: Japan in the Wake of World War II" by John Dower. "Hirohito and the Making of Modern Japan" by Herbet Bix is also excellent in this regard. In this book, the perspective comes from Hirohito and the top of the Japanese government after the war. While it is only a section of this book, I think you might enjoy the whole thing. Any textbook on Modern Japan will also have a lot of focus on that as well, so if you want any of those recommendations I'd be happy to help.
I really liked William T. Rowe's "China's Last Empire: The Great Qing" which is part of a 6-volume series on Chinese history.
Not just one book, but a series of books:
History of Imperial China (multiple authors but all edited by Timothy Brook)
This series of 6 books covers all of the major dynasties of Chinese history, starting with the Qin 221 BCE-206 BCE, so not quite prehistory but it still gets back there.
For a single book, you could try China: A History by John Keay. I have not read this because I, in general, do not like these large sweeping single-volume histories, especially in a country like China.
There is a series of books that might pique your interest a little, it is called "The History of Imperial China" and each of the 6 volumes are written by the leading historians in the field and are all edited by the great Timothy Brook. If you are looking for more Ancient China, then the first 2-3 volumes should be enough for you. None of the volumes are extremely comprehensive however, they only really focus on a few areas of each dynasty that the writer has more expertise in.
You could also attempt to read through a translation of the "Records of the Three Kingdoms", which is one of the most official and authoratative sources of information from the period.