i like them more for their writings and theories, also trotsky is probably my favorite out of all of them, and the most destructive thing he did was give hope to the red army (speeches and such) in the civil war
luxembourg is another of my favorites....and my favorite example of revolution is the paris commune - but i think that the ussr is probably one of the most important events of modern history and needs to be studied objectively.
i think his motive in WWII was probably the only thing he could do as a statesman, regardless as to his personal feelings - i like the side of FDR that tried to initiate social safety nets and took in refugees, but the US could've done a LOT more, even before the war itself, in helping out the fleeing germans (not just german jews).
i think the allies should've taken out the fascist state as soon as it became elected, but, that's to be expected, the fascists were more appetizing to the west than the communists.
(ALSO remember FDR was more preoccupied with defeating the japanese, he helped in defeating germany A LOT, but he was more focused on japan - if they concentrated on taking germany, the ussr might not have "won the race to berlin". remember also that it was the ussr that defeated the nazis, NOT the us in the end)