The comparison to Nazis and colonial America was not made, no. The comparison would be disingenuous, imo. The Nazis sought to rid the world of the Jewish people. Black people even if hated in America were still wanted on the base level of labor. While some Jews were used for labor, it was only temporary. The main goal was always extermination.

Yes, actually. The Russian march back to Germany was very well documented, however overshadowed by D-day in our textbooks.

No, that point was not made, nor was Oppenheimer's guilt or any sort of reluctance. I didn't personally get that info until I listened to Hardcore History.