I don’t think Wu Nan is pretentious at all. It is impossible to generalize about the immigrants’ experience and to create a “typical” Chinese immigrant. Each one has his own interpretation of American dream. For Wu Nan (or Ha Jin), the American dream means he could write poetry, which he had never dared to dream in China, because he grew up in a time when free expression and individual voice were oppressed. I agree with you that “A Free Life” is a personal journey, not a generalization of Chinese immigrants, which is not the purpose of this novel.
I like the metaphor “a lemon on an apple tree”, because apple tree is considered a native tree of America – a nice choice. None of Chinese immigrants is purely yellow or white on the inside. Along the way, we all lost a part of our cultural identity, and that is why we all have experienced reverse cultural shock when we went back to China either for a visit or for a permanent settlement. Yet we really can’t “squeeze all China-ness out of our blood”, and a part of the old country stays in our blood whether we like it or not. I admit that I am a yellow lemon on a big apple tree, instead of a banana (haha).
A few bricks:
1. Nan Wu is trying to penetrate the main-stream American society by improving his second language competence and eventually rising (rise) up from his current social status.
2. Suppose in 50 years, when Americans swarm to China and settle there – sounds a little bit strange, but I am not sure how to change it.
3. give up their roots completely? – sounds a little bit strange, how about “uproot themselves completely?”