Survival in Auschwitz (If this is a man) Theme of Race

In Survival in Auschwitz (and in history), Jews are the primary victims of Nazi persecution and are targeted for extermination for the mere fact that they are Jews. This ends up being really an arbitrary distinction, since many Germans were themselves of Jewish ancestry (and we're looking at you, Hitler). Notice how Primo is set apart from the other Jews in the Lager, though: he admits that he doesn't really identify as a Jew, but rather as an Italian of Jewish descent. Because of this, he doesn't participate in the religious or cultural activities that the other Jews use to try to hang onto their heritage (like the Storyteller and the prayers that many of his fellow prisoners recite).

1. Why does Levi use a lot of quotations from Dante's Inferno, rather than from the Torah or other Jewish writings?
2. What is the significance of the term "mussulman?" Keep in mind that this is the German word for "Muslim," but in the camp it comes to mean an emaciated prisoner weakened beyond all hope.
3. Since Primo himself clearly doesn't self-identify strongly as Jewish, where do we see a sense of Jewishness in this book?
4. Why is Primo so surprised that the Nazi soldiers could hit a man without any trace of anger? In what way does this relate to the issue of race in the book?

Primo doesn't really seem Jewish at all, and is constantly set apart from the other Jewish prisoners.

Defining Jews as a race, rather than a religious or cultural group, allowed the Nazis to define anyone with any Jewish ancestry at all as Jewish, even if it was a distant grandparent or even if the family had been practicing Christians for generations (source).