I, and as far I could tell everyone I went to school with, took very different lessons away from Nazis than, presumably, everyone that ended up in the Ivies or some pretentious little liberal arts school.
Which is to say, I don't think "most people aren't consequentialist" is remotely sufficient to explain why some people (such as myself and classmates) took the generalized lesson that racial supremacy is bad, and so many others took away the lesson specifically white people are the root of all evil.
There was also this thread a couple weeks ago, on the nature and scale of hate speech, in relation to recent actions by the NBA.
To summarize, the "different reactions are fine" side is that for historical reasons, only slurs with historical weight are of honest concern. "White slurs" don't really exist, don't count, and/or as so minuscule compared to other slurs one should just ignore them. To care at all is to focus on minor problems, when you should grin and bear it to fix bigger problems.
I, on the other hand, think that lesson can and should be generalized, and that while on some Cosmic Suffering Scoreboard slurs do not "hit" races necessarily the same way, they are obviously of a kind and lead down the same paths. We should prevent that historical weight from being built. "The best time to plant a tree is 20 years ago. It's easier to prevent a rock from rolling than to catch it halfway down the hill with momentum."
Question, the first: when should specific lessons be drawn (the Nazis were bad), and when should general lessons be drawn (racial supremacism is bad)? Is there any usefully-generalizable (ha) guideline to this? Is it conflict theory turtles all the way down?
Let's begin by asking why history lessons (specifically in school) should be imparting any moral or ethic lessons and on what authority?
Now, obviously American schools always have, to varying degrees, had a component of building a shared culture and imparting common American values. And I actually think that is relatively good and necessary for a democratic nation.
But this goes back to the tensions I have spoken about between the the democratic and the liberal parts of liberal democracy. Imparting an authoritative (which anything coming from the power dynamic of schooling is, by nature) shared value system and moral lessons is democratic but quite illiberal on its face.
The problem here is that in previous generations this shared moral and ethical framework, American Values was fundamentally Christian at its foundation.
In that context, the First Amendment essentially muted particular and sectarian theological claims, while allowing a general Christian epistemology to be transmitted from the classroom and other institutions of authority.
But now that our culture, and especially our institutions are no longer Christian (especially not in cross-denominational aligned coherence), we still have this idea that its ok for institutions to broadcast ethical "lessons" or teach "values" no longer defined in theological terms. But now instead of muting the wrinkles of a shared foundational ethos, the first Amendment myopically excludes explicitly theological moral epistemologies, while these secular "frameworks" are allowed to be expoused from instutions as meta-values, above, beyond, and protected from personal convictions.
So I ask again, on what authority? The problem you are noticing and penetrating into is that institutions are broadcasting morality to a divided culture and claiming a self-referential epistemic authority to do so. They are fighting each other over the mantle, and generally, I find the first Amendment to be broken by this.
Liberalism got rid of the shared Christian epistemic foundation of our democracy. Fine. But now new ideologies have come in through the backdoor by not calling themselves religion and are fighting to be the dominant epistemic force of our schools and institutions in an all out war.
There is a missing social technology causing this rupture, where religion is forbidden as a foundation for moral claims, but non-religious moral claims are allowed to have institutional monopolies. Questions like "Is Woke a Religion" penetrate into an important point that the difference between religious and non-religious value-systems is often immaterial in terms of protected freedoms.
You can either allow currently protected institutions to teach and discriminate on any values you want, religious or otherwise, forbid them from favoring any values whatsoever, or re-establish a dominant value system that has prima-facia cultural monopoly. We are in the a bloody fight of the 3rd right now as progressivism is winning out.
In light of this view, all three of your questions are subservient, imho, to which of those three options you want to take.