"There were rather a lot of them, you know"
Ok, fine. Take out the atrocity-committers, high-level people, and a few gauletiers to make a point. The real low-level Party members (esp. those who joined to get better jobs or avoid losing the ones they had), without a leader to rally around, shouldn't be too much of a problem. If not, Rommel, Canaris, and friends could use the same secret-police measures the US used in "de-Nazification." Remember, they're still a nation at war--some sneaky stuff could probably be gotten away with.
""the disturbing power of the German state and the German threat to European stability and freedom"
The US is several orders of magnitude more powerful than Nazi Germany and are WE a threat to Europe's "stability and freedom"? If so, do we need a war to the knife between ourselves and the "international community" to deal with us?
What matters is not power, what matters is INTENT. The US didn't do much outside of the Western Hemisphere until the Spanish-American War and WWI and the French actually sent us the Statue of Liberty as a gift. Even then, the US in terms of sheer industrial mass, could have laid the proverbial smackdown on France. Removing the Nazis removes the "intent" to dominate Europe and (maybe) the world.
"I think by now this should have worn off. Have a look at Bartov's monograph, THE BARBARISATION OF WAR ON THE EASTERN FRONT (IIRC), which analyses divisional war diaries."
True. Put basically decent people into a BAD situation (like war, or the collapse of civilization, etc) and these decent people are capable of doing VERY bad things. To use the film "28 Days Later" as an example, do you think that Major West, when Britain was fine and peaceful, would be capable of letting his soldiers rape women? Probably not, but when Britain has collapsed into plague-ridden anarchy, then...
"The anti-Nazi Germans were no subsitute for the USSR"
If they were successful and managed to topple Hitler, why not? Would you rather have the 21st Century's first terrorist state controlling 2/3 of Europe's land mass, as what happened historically? If the anti-Nazi Germans fail, then so be it; bomb the Nazi SOBs into the Stone Age.
However, according to "The New Dealer's War," other means were available. An exiled German bishop, for example, wanted to bombard Germany with leaflets telling the Germans that if they continued to tolerate "the pogroms" (the Holocaust), the same thing would happen to them. And in the East, it ultimately did--see "A Terrible Revenge." However, the US wouldn't let him.