what were major faults of FDR? Especially during the war?
I think his major fault during the war was to inter Japanese-Americans. He could also be faulted for allowing the atomic bomb to be developed and weakness toward Stalin and the Soviets for their imperialism.
Check this article, recognizing that it is definitely biased against Roosevelt.
http://www.intellectualconservative.com/2008/10/28/franklin-roosevelt-rerevisionism/