I mean, maybe, but his wife's biography of him paints a much different picture. It could be that her biography reflects just their time together, which would have been before the 30s.
Politically yes, but it's well known his writing stayed pretty racist (even the later stuff). There's this funny trope that people with a Germanic last name are rarely evil in this writing, but Italian, Slavic etc last names are often depicted as bad people.
It's so pronounced that the people worshipping Cthulhu were often depicted more horrifically than actual Cthulhu. And it's obvious why: that was Lovecraft's biggest fear.
Separate the art from the artist. Many people who are shitbags produce good art and I can still enjoy the art without endorsing them. He was and is (and perhaps always will be) the GOAT in cosmic horror.
The idiom "separate the art from the artist" actually means the opposite to that. It means that it doesn't matter what the artist intended, if it caused offense then it is still offensive. Rather than, it doesn't matter how much offensive stuff put into the art if I don't find it offensive then it's fine.
That's not at all the commonly known meaning. It's differentiating the art from the actions or beliefs of the artists. I like plenty of art, music, literature, created by awful people, but that doesn't reduce the meaning or importance of their work.