Dear Jimmy,
thanks a lot for your E-Mail. It's always a good feeling to communicate with somebody else about one of your favorite topics.
So let me answer your question about the meaning of the German title of "Pinwheel". "Die Tanten winken um halb acht" means - directly translated - "The Aunts Wave at Half Past Seven" (or "Half Eight", if you like better). The title, as Russ Conway explains in the German version of the episode, means the sentence that is used by a new agent to introduce himself as a new "member of the team", as Melanie does to Kelly and Scotty. In the English version, as Bulwer-Lytton was so nice to tell me, the code is "calendar, whiskey, and rhyme".
As to "It's All Done with Mirrors": yes, I have seen the episode in English (it is included in the German first season DVD box set with German subtitles). I, too, like the episode very much because the viewer is guessing until the very ending what is stronger - the banter between Kelly and Scotty or Karolyi's brainwashing.
Unfortunately, I have no idea what reasons there were not to translate the episode into German language. To my mind, there is nothing in it that has to do with Nazis or a Nazi background.
I hope I could help you a little bit.
Paully the Kid