Yes, I think it was probably appropriate for China to pull "Django Unchained" from their movie theaters. The people in China live in a very different place and culture than the United States and the language and violence used in the movie are something that they are probably vastly unfamiliar with and would not understand.
It's a historically based movie with a great deal of fiction in it. I don't see how China could have possibly found this offensive. China is a very strange place with some incredibly weird concepts for censorship. I don't think Django Unchained really needed to be pulled from any movie theaters.
If people want to see it, people want to see it. Like your typical flick from the director behind it, there's a lot of violence, it's edgy, so on and so forth. So what? Pulling it from theaters won't make people disinterested in seeing it, it'll make them that much more dedicated to finding a way. And they will. You accomplish nothing.
The awarding movie 'Django Unchained' deals with the issues of slavery in the Old South, a man's desire for freedom and challenges to the concept of freedom vs. The obligation to follow the laws of the land. The Chinese government feared that the subject of freedom would cause problems with the citizens when they were shown that men were intended to live free! The movie should have been allowed to play.