On that note, any politicians who you see being prominent in the radicalized DNVP?
Watergate was skullduggery against political opposition, so nope.
The DNVP will feature a few names you might know and I have a few lined up. Hans Frank, IRL head of the Generalgouverment in Poland, will be a prominent member. It won't just be "the leftover Nazis", though, because the Nazi party still exists, albeit not quite as you know.
I'm hoping Lettow Vorbeck actually manages to fix the German Economy after the great depression, unlike what happened IOTL (which was, essentially one massive scheme that needed to keep growing to sustain itself, with even the Germans still worse off by the time of the war than they were 10 years earlier)
On another note, What's the old lion's policy towards his eastern neighbors?
Foreign policy is coming up in a few chapters in detail (once he is actually in power) but on the topic of Poland specifically: Von Lettow-Vorbeck believes strongly in the idea of defeat in WW1 being the result of subversive elements. One of those supposedly-subversive elements is Poland, who, in the minds of many, repaid German generosity (liberating them from Russia) with betrayal when they seized Posen and took West Prussia and Upper Silesia. So, on the one hand, von Lettow-Vorbeck believes very strongly that much, if not all of the German land ceded to Poland is under illegitimate ownership and that the solution must be rectified before further action can be taken.
On the other hand (and this is based on how I have chosen to portray him rather than any information I could find on his politics), von Lettow-Vorbeck is a big believer in
Realpolitik, due to a combination of when he grew up and how he fought in East Africa. In other words, he has big dreams but doesn't let them override his pragmatism. He might WANT to retake the 1914 borders, but he won't endanger everything Germany has rebuilt for it, and he understands that there are longer and bigger goals than cities and regions. He, like Bismarck, wants to rig the game before he plays it.
(Not that he is above a bit of spontaneous action if the situation presents itself. No risk, no reward is not an entirely illogical concept.)