To me, there are really only two major themes in this book -- Holden's loneliness because of how fake he thinks the outside world is and his struggle with himself as to what he really thinks of that outside, adult world.  Both of these can be seen in these chapters.

In these chapters, Holden comes to New York.  He tries to find people who will want to hang out with him, people he can interact with.  But no one will really interact with him in the way he wants.

Faith Cavendish doesn't really want to meet him.  The three women from Seattle tolerate him for a while but then get tired of him.  The taxi driver gets annoyed with him.  This shows how lonely Holden is because he cannot interact with the outside world in the way that is expected of him.

We also see his inner conflict in the way that he keeps trying to hang out with people even though he says they're phony.