Mario, I am American born but just got back from Germany last month. I understand your sensitivity to the possibly offensive humor in the ep. The WHOLE episode is a kind of a joke since television doesn't provide an adequate budget to depict the large crowds necessary to create the atmosphere of a "Nazi" planet. There just weren't enough extras, and the whole episode trucks in almost pure cliche. It's all so silly, humor just naturally bubbles to the surface. This is the reason why a large number of fans find Patterns of Force "corny" and insincere. You just can't take such a serious subject as Nazism and turn it into a plastic screenplay for a television episode. It is easy to understand why this episode was not shown in Germany for decades.
I am constrained to point out that other Trek episodes offend specific parties. For example, Shatner joking in "City on the Edge of Forever" that "My friend is obviously Chinese". Or in Turnabout Intruder when Kirk says that captain isn't a position that Janice Lester "merits by temperament or training." Turnabout Intruder is a total turnoff to women, I know that. And I know that "Elan of Troyius" is highly offensive to some Asian women. And of course if I was a Vulcan, I would indeed find the entire series highly offensive, since both Kirk and McCoy are constantly taking racist jabs at Spock.
~ Mr Atoz