Yes, I agree with all of that. I think unfortunately school education tends to focus more on the horrors that were comitted, than the living breathing cultures that were harmed. That is, if they aknowledge it at all, and not just happly toot on about the countries great achievements, instead of facing some uncomfortable truths.
Speaking from my own perspective, we did second Word War every year in some form all throughout secondary school. Be it in actual history lessons, reading Anne Franks diary for german lessons, doing a play about Auschwitz in theater class (and meeting the real life holocaust survivor the play was about, wich was amazing), looking at the econimic and geographical consequences of the third reich and examining the cultural and sociological impact in geography and social sciences. All of wich is important. What we didn't do is visit a single Synagogue. Or learn anything about jewish tradition and religion.
We looked at the piles of shoes, all that is left from the people the Nazis killed, but we didn't look at living breathing jewish culture in germany.
Cultures oral history especially tends to get dismissed and skipped over. Native american history and culture as well as current conditions should definetly be tought and examined in school. As should african american history and cultural movements imho. But the US school system is an underfunded clusterfuck, that allows for blatantly false 'science' to be taught based on an evangelical christian bias, atm so there is a LOT of fixing required.
I also agree that we don't get far picking on superficial issues, but I also came to realize that clothing carries meaning, a lot of the time more than we give it credit for at a casual glance. For many black slaves a fine suit was the diffrence between making it to the North or spending the rest of their life in servitude and a war bonnet was and is a sacred item that deserves to be treated with respect. So if someone is hurt by stupid drunk people appropiating their culture and legacy, all the while ignoring all the very real problems that exist due to was done to that culture, I think they have the right to speak about it. Ideally in such a way as to educate and alert people to the actual, way bigger problems that are going on.
I have a deep admiration for Germany and how its handled its history following the wars. May even a bit too much being so concerned with Dritte Reich imagery, but I know heart is in the right place. May not be perfect, but as you stated about US education system it is progress.
Part of this view comes from American culture where locally we have festivals to celebrate local cultures of Mexican, Irish, Italian, and especially German culture. I wore a dirndl and drank beer from a glass boot which may be stereotypical and even offensive to you given I have no direct German heritage, but it was more of sharing and honoring each other to become closer. I do think intent and attitude matters, not just the imagery.
The challenge with these issues is we are often arguing about end products and the divide comes from very different understanding of history. For example, if all someone knew about Germany was the second World War that vacuum of context would create a very distorted view of your people. I'm not sure how much progress or valid use of mental resources it is spending outrage on a symptom if we ignore the causes of such mindsets. It's not an easy issue to resolve given as a species we naturally want to take reductionist views of others.