re: 5
why?
We know Wagner now as a composer. By the musicians’ opinion he is up there placed in a classification anywhere from 4th place down (after Beethoven, Mozart and Bach) in the top 10 or at least top 20 for sure - opinions vary of course.
But he was not just a composer. He was a philosopher, very vocal and very much beloved later by the fuhrer and Nazis - not just as a composer but specifically for his loud uncompromising anti-semitism.
There are calls to separate music from politics and enjoy the music regardless of the composer’s persona. OK, I personally indeed do this for other casual anti-semites like Chopin or Tchaikovsky. I draw a line for Wagner. I can’t make myself enjoy his music.
You will find a ton of material on the Internet googling “Wagner’s antisemitism”.
Check for example this very reserved in tone article: http://www.jewishvirtuallibrary.org/jsource/anti-semitism/Wagner.html