Interesting subject, thanks for your input.
I have my 2 cents about it though. Nietzsche was indeed often mentioned in German circles at the time, particularly through the word Ubermensch; but this took on a different dimension when a certain Englishman got hold of it and changed the rules a bit.
As shown in one of your quotes, Nietzsche's Ubermensch most important characteristic is the quality of his soul. This is indeed where Nietzsche alludes to human inequality, a touchy subject for modern Western liberal society, but the Germans at the time took it in a very material, racial sense. And they got this idea mostly from Lothrop Stoddard, who wrote a book called 'The revolt against civilization; the menace of the Under-man'.
Under-man=Untermensch. Stoddard rolled with Nietzsche's definitions, but changed them along the way to strictly racial view, where white civilization should be preserved over the rise (in numbers) of the non-whites. Stoddard was no fan of Jews either.
Good review, hope to see you do more of this kind of stuf in the Book-review section.
RE: Nietzsche and the Nazis: A Really Interesting Book by Stephen Hicks