Yep, I agree with basically everything you said, Ke3. I have no issue with the casting of any of the actresses I mentioned, and I think both shows should have diverse casts. It honestly just confused me that people seemed to think Pfeiffer's casting was more 'authentic', and it seems like there's a different kind of racism at play there. Like, she's 'exotic', so she's somehow automatically more authentic in the role. Or, all POC are more or less equivalent, so it's fine (and, like you pointed out, I don't think Eva would have even identified herself as a POC). I saw someone raving about the revival with Elena Roger, saying that 'we finally have a brown woman playing the role', which...Roger is blue-eyed, pale, and has light hair.
Also, in terms of KotSW, I think Molina is pretty strongly implied to be part of the ethnic majority in Argentina (who were mostly Italian/Spanish/French). Especially in the book and movie, he romanticizes Nazi propaganda and talks about people with dark skin in a pretty stereotypical and derogatory way. There's every indication that he doesn't view himself as a POC either. In the musical, they do cut that Aurora is in a Nazi movie, but she does play a Russian princess in one of the films.