"Nazi labor unions would prevent large-scale slave labor"
Because, you know, that's just exactly what they did in peacetime. The pre-war concentration camp population did not amount to anything even close to a significant part of the work force. Nazism worked not primarily because they kept the population in fear, but because they kept the population in Germany content. Which means, well-employed.
"no one would rebel against the Nazi-American state, becuase it would be rich and economically successful."
There is no mention of foreign wars, and what military kit we're shown in the show is light paramilitary stuff with a few helicopters thrown in for good measure. Nazism in the historical context was bound for bankrupcy because it used all available funds on the military in apprehension of coming conquests. That's not the case here, because there still *is* a Mexico after 70 years. There's nothing making the economic policies of a contained Nazi state impossible; without the impetus of a massive military upbuilt, we're looking at something comparable to European social democracy in an economic sense. As for the rebellion: because, you know, people usually don't rebel when they are content and at least moderately well-off.
Oh, and the guy's whole bit about how the Nazis never wanted to kill Jews, homosexuals, Gypsies, etc., but only throw them out of their country seems a bit like wishful thinking
Considering that was pretty much what the official policy of discrimination's goal amounted to - and which worked pretty well - that's kinda you arguing against historical evidence.
the Holocaust may not have been planned from 1933 or anything, but the idea of Lebensraum, which pretty much necessarily involved killing a lot of the locals, was there from the beginning.
It really didn't. Pre-war Lebensraum talk, if you get down to the specifics of what they were
actually talking about, usually concerned the Sudetenland, Austria and the territories in Poland. If modern holoaust research has proven one thing, then it's that the Germans more or less stumbled from one measure to another because the influence of an ideological core clique and military success coincided for some while.
Especially prominent is Prof. Hans Mommsen's interpretation of the decision process that eventually resulted in the Holocaust, as a process called "cumulative radicalization". The Nazi regime - this is his thesis in brief - had entangled itself into constraints that by themselves demanded more and more radical approaches as time progressed, finally ending with the "Final Solution".