Your criticisms of FDR reek of Monday morning quarterbacking. They remind me when intellectual leftists criticize the founding fathers for not abolishing slavery. Most didn't like the practice but they didn't know what to do about.
FDR needed the Soviets cooperation to get rid of Hitler and defeat Japan. He achieved that goal. To turn on an "ally" after a brutal war was not advisable at the time.
Don't get me wrong, they really were up to evil and it is probably a good thing we defeated them and Germany.
On the other hand I recall reading in Churchill's 6 volumn history of WWII that we had not accomplished anything at the end of the war. He said they went to war over Poland and ended up giving it to Russia which was just as bad as the Nazis.
I will call a spade a spade and FDR was;
1.)The founder of the nanny state.
2.)The founder of the Soviet Union and modern marxism.