Nixon wasn't all that bad by today's standards (god my dad, who is hippie artist born in '47 would kill me for saying so, but compared to NOW...). In addition to the things you point out, he also got us off the gold standard, something Europe did decades previous, and he also started the "War on Poverty". Both of these are antithetical to the Modern Republican ethos. FDR, as far as I've read, was the moderate Democrat of the time. The business elite hater him, but they assassinated Huey Long, who was poised to challenge him.
As for WWI and II, I can't recommend The Guns of August high enough, if you're at all interested in that history. Its a narrative history of the 1st month of WWI, and gives great perspective about the interrelatedness of the royal families of Europe, why war erupted, and the setup of WWII.turned me onto it. Its a history that is not told in enough detail in schools here, as it gets lost between the Civil War and WWII, but is absolutely fascinating. And, our world today is shaped by it, as it was the end of WWI that shaped the borders of many of the conflict areas of today (Mideast, Balkans, Africa).
It's one of the best books, history or otherwise, that I've read.