“US oversight of denazification lasted for just two years; and then it was just handed over to Adenauer, who declared it “over” three years later. Think it was executed properly?”
Probably not, and probably for the same reasons that Reconstruction in the South was carried out half-heartedly and abandoned not long after. The Union was plum worn out from the bloodshed of the war, the Army had been drawn down to a tiny fraction of the Grand Army of the Republic, and everyone wanted to get back to the business of business. The guards at the War Crimes Trials were in fact, former Estonian Waffen SS, no fooling. Because the occupying powers had such severe manpower problems after Demobilization. I’ve not read much on the Werwulf guerilla movement, but a few documentaries I’ve watched indicate that the action in post-war Germany was about as hot as Iraq was more recently. Lots of terror attacks on Allied soldiers. This was met with brutal reprisal. Anyone caught engaged in pro-Nazi sabotage was hanged, unlike our more recent failed counter-guerilla campaigns. While the civil de-Nazification program could have probably stood to go on longer, there was the war exhaustion to consider, and the election of Adenauer greatly calmed German resistance, as they finally had their own elected government.
The mere existence of an “elected government” does not mean no tyranny, of course. Things almost came to a head with Willy Brandt and his Soviet shenanigans.