1. Phillip Glass (the K was a typo (my apologies))
2a. No that example is better than all you have offered so far so you first...don't make me post Slayer live...don't make me....
2b. You mentioned flashy guitar work of melodic DM as being over the top and purist metal guys like me shun the simple progressions and incoherent screamings/growls of metalcore
3. See we agree in the end.
Btw, Wagner was a prick and disgusting human being on several levels including the belief in eugenics and the whole final solution movement of the Nazis. I agree he is a musical genius and was the first director of a big budget hollywood production (the Ring Cycle: combining the poetry of operta and the epicness of mythology with a sprinkle of German technical virtuosity) but the man was just disgusting....