As Eminem would sing, "Guess who's back... back again."

Thanks very much for the attention I've gotten due to this post, and I'll confess that the idea of drawing a line between "the beginning of China as a nation" and "the beginning of Chinese civilization," is something that did not occur to me before. Though it makes sense, actually.
For example, Rome and Hellenic Greece no longer exist, but their civilizations do, in the form of the Modern West. Ergo, I suppose it makes sense to think of the Warring States (the ones I call "Proto-Chinese") as being from Sinic Civilization, making them part of China's cultural history but not part of China's national history.
Of course, given that these states had at least as many cultural differences with each other as... oh, say, Sparta and Athens did with each other, there's room to dispute this, but it does at least make sense.

As always, it's interesting reading your perspective.