One of the more infamous notions of purely cognitive S-W that dorm peddle that is entirely discredited is the idea that people who speak gendered languages tend to associate "feminine qualities" with feminine nouns describing even inanimate objects, and "masculine qualities" with the reverse. This has been measured in various ways and is simply false.
I would bet that your example of "foreigner hatred" vs "xenophobia" would also turn out to be wrong if studied. The much, much more likely reason Japanese people don't consider themselves xenophobic is that people don't typically think of themselves as holding bad views. I would bet lots of English-speaking white nationalists also don't consider themselves xenophobic for the same reason.
Finally, I think your outlook on the level to which Hitler manipulated the German people is highly optimistic about human nature. I think it's unfortunately quite clear that people didn't need a lot of sophisticated convincing to do what they did in WWII, they wanted to do most of that and all they needed was someone who would allow and organize them. And to be clear, I'm not only speaking of the German people here - atrocities against Jewish people and other minorities were committed in many European countries where people didn't speak an ounce of German, they just needed to be let loose. Including, shamefully, my own country (Romania), to be clear that I'm not just pointing fingers at others.
