1. What happened to Mel Brooks, Jack Kirby, Joe Simon, and Charlie Chaplin? Well known for their famous anti-Nazi works?
Still successful, although with slightly different works than OTL. Expect more villains in comic books to be depicted with really silly mustaches and/or communist stars.
2. What happened to black/other non-white, Jewish, female, and queer communists? Did they change their political ideologies once they realised that Moscow was allying with a nation that pretty much wanted to murder all of them? Along with the Nazis/Pro-Nazi groups outside of Germany?
There's as many answers to this as there are minority communists. Some would have denounced the Moscow line. Some would have said "that's not
real communism/socialism". Some just wouldn't have given a damn (if Russian neo-Nazis can exist today, other strange combinations of ideology are more than possible!).
Especially later in the war, most communists of all sorts became less inclined to advertise their communist beliefs so they wouldn't be outcast by society. Some would have dropped those beliefs entirely, others would have just found another left-wing group that suited them and carried on mostly as before.
3. Speaking of Queers, how are LGBT Rights like ITTL?
Depends a lot on where you are. In the West, full acceptance has either been achieved or is on the way to being so by 2020, although gay marriage wouldn't be supported nearly so much as OTL and would still be quite rare (unity and friendship with your fellow countryman, rather than political partisanship, is a defining characteristic of a lot of these societies, but radical social changes that might disrupt that are less likely to gain support due to the fear of rocking the boat).
Russia's theologians would still be fiercely debating the issue - no consensus has been reached among the church elders and without instruction from them, most common people haven't yet come to a decision either.
Japan's society basically denies any form identity other than nationality - a gay person from Korea would be much more likely to tell people that they were "from Korea" than that they were gay. Due to the need to get at least 2 of the 3 major nationalities (Japanese, Korean, Manchurian) on board with a majority in the government to get enough votes, passing any sort of social reform focused on anything but nationality tends to be a very slow process.
Fascist Italy, Ukraine or Austria... there's no death camps, but let's just say you would probably want to either emigrate or stay "in the closet" if you identified in that direction.
- BNC