Although there were a few things I would have like to see differently, I liked the book a lot.
Re: Harvey's death. When the girl travelling by herself called him a "creep", for some reason I was waiting for something to happend that she would kill him or that he would go to see the sink hole and fall in to it and slowly die as the safe popped up.
I believe Susie fell to earth no only to have the positive and caring physical side of sex, but to also feel loved by her childhood love that she never lost feelings for. She had years of watching others have sex or making love, so it was not a foreign idea to her.