"The Holocaust" usually refers specifically to the killing of Jews and not the broader genocide, though this varies. It is also worth noting that about 1 million Jews were killed on the eastern front and are correctly counted as part of the 6 million, but overall if anything you are probably lowballing non-Jewish victims.

I think part of the reason for Jews being a focus of the discussion is that they were the face of the vilification and the Nazis went to incredible lengths to capture or kill every Jewish person they possibly could in the territory they controlled, both in relatively stabley-held civil society and recently taken-over military conquests, which is pretty unusual compared to other genocides. Jews were also far and away one of the most brutally killed and persecuted on a per capita basis compared to other groups (though I think Romani were in a similar boat there but Europe just hates them).

It's complicated, I wouldn't use the historical part here before 45. Germany is since the Marshall-Plan deep in the hands of US politics. If Palestines are not allowed to demonstrate in the US, then it's not allowed in Germany.

Any critism about Israel-poltics from Germany would be attacked with antisemitism.

This conflict is highly complicated for Germany, foreign minister baerbocks abstention at the UN resolution earned hard critics from Israel, but German people approved this decision because it shows the inner conflict between pro Israel and against a genocide. It looks like both isn't possible anymore. And the USA should decide quickly, germany would follow as always.