没错, most Tibetan Buddhists are Tibetan :p
There are a lot of Chinese looking folk in the Himalayas, particularly in regions of Nepal close to the Chinese border and Sikkim. Even as far as Kolkata you can see traces of Chinese phenotypes
I agree, and it's always difficult when discussing China to distinguish between objective history and constructed history. However from a sociological perspective, the "lived" history is the constructed one; it's what Chinese history textbooks teach and Chinese 大众 believe, thus what influences modern culture, irrespective of its artificial origins.
"Culture...is not static. One imagines a range of possibilities—what might be called an “arena” - in which a field of meanings is brought to bear by potentially competing actors, and any stability is sustained not by inertia but by authority and hegemony" (Myers 2004)
However that's not to say that contemporary Chinese culture is 'inauthentic', just that it's influenced by current power hierarchies as much as history.
>"Chinese culture" never extended beyond a bunch of scholars and civil servants who lived in a bubble and spoke some form of 官话 and wrote in 文言 that had nothing to do with...the culture and language of the vast majority of Chinese
Interestingly enough, 人民日报 had an editorial about China progressing from a 精英化阶段 to a 大众化阶段, but in regard to the tertiary education boom of the late 20th century (沈杰 2004), so maybe there is more change yet to come (although I wouldn't exactly describe the education provided by third-tier unis as "精英")
沈杰 2004,‘中国大学毕业生就业:现状、问题与前景’,人民网,2004年11月12日《people.com.cn/GB/guandian/8213/40408/40412/2983578.html》
Myers, F. R. 2004, 'Unsettled Business: Acrylic Painting, Tradition, and Indigenous Being', Visual Anthropology, vol. 17, pp. 247–271.