According to my friend's description (he has a lot of African friends), they do appreciate what Chinese government did for years. As compared to the sponsorship from those western/developed countries, Chinese government do have some contirbutions.
For example, funds from western world will help building a bridge connecting both sides of the river, but they rarely upgrade those roads connecting to the bridge. On the other hand, Chinese sponsorship will help building the local road network to the remote areas. When it comes to advertising, magazines from western world will take photos for the bridge, but they merely report what the connections are like...
When you have invested billions of dollars on a project, stability becomes a big factor to your decision making process.
If there're enough local workers that are as skillful, cheap and obedient, I don't think they need to export workers from China... What they do will be exporting management staffs to those countries instead...
I agree, individual culture has to be respect. But, at the same time, the premise has to be based on an unified country. Today, when you look back to Canada history, it takes days for this harmony to settle. I'm not saying the Chinese government is doing thing properly, but it's a required step that they should take.
According to the history I've learnt, there's no purified Hans tribe nowadays. The Hans tribe is actually a big hybrid which is unified under the Hans culture.