You wrote: "Sorry, my friend, as a half-German myself, there is something inherently psychotic in the German psyche. They are a militant, rigid, hard people."
This is a pretty strong statement to be made without providing any further analysis.
Moreover, I must ask whether or not you hold dual citizenship or were brought up in Germany? Otherwise about 30% of the American population can claim to be at least some part German. So obviously it is not a genetic thing.
You point out that there is a cultural propensity toward militarism. I agree. The Prussian culture was formed by teh constant need to fight the hordes of the East. The Teutonic knights fought back the Mongols and their Austro-Hungarian counterparts the Turks - just to name a few. If it were not for that culture neither you nor I would be here.
That much said, the actions of Germany and the German people during WWII are never to be forgotten or belittled. However the lesson you should learn is not that "Germans are inherently psychotic" but rather even cultures that appear to be completely civilized and at the pinnacle of civilization are capable of total barbarism.
America is not immune. It takes people like many here at FR to constantly make sure that individuals never get into power in United States that would use its unprecented power to evil rather than good.