Hi Horst. I was puzzled by your remarks on the Jewishness aspect. There are plenty of Jews in Germany who see their Jewishness as more an identity which is imposed on them by others, be they Jews or non-Jews. For these secular Jews, their Jewishness is felt as an accident of birth - it is not a key to their identity.
Gutman can only be the success he is, precisely because he plays down his Jewishness. This would be true in most western democracies, but probably still even more so in Germany -even if it is 70 years after the war.
For the Nazis, no 'characterization' of his Jewishness would matter anyway. The fact that he was a Jew meant that he would be a target, no matter how little in Gutman's life this played a part.