Billy, you refer to China as an old country. From the little I know about about your history, It seems to me China is a very old culture but a young country.
Wasn't China always a bunch of different ethnic groups with different dialects and customs?
Weren't these groups constantly shifting alliances and power struggles?
Didn't various parts of China struggle under different foreign powers for several hundred years, not really becoming a single country with a national identity until the 20th century?

China ethnic groups
 

Yeah, there are 56 ethnic groups in China. Many ethnic groups have their dialects and customs. Now many dialects and customs are losing. Many young generation speak mandarin and use the industrial products adnd like eating west food. In faraway place the dialects and customs are not affected.

In fact many ethnic groups hope to have a peaceful life. In Tibet and Sinkiang there are some alliances and power struggles because the out counties provoke them to fight. They hope to these palces separate from China. Almost people would like have a strong and united country.

Before P.R. China bulit they lived in their own scopes. They would try their best to protect their area if different gorups want to occupy their area. In China history every dynasty had a united time when every goups had a peaceful lifes. After days went on they struggled to get more strong power, large area, ect. Every dynasty bulit with blood and tears. Now we dould not like fight, but comforable life.

I realize that what you're telling us, is China as you understand it and you're not speaking (typing) as the official spokesman of the Chinese government.
In the case of Tibet, I think you've bought the party line. I don't think we can agree on that one, but I'll have to do more research.;)