One factor that I think isn't being taken into proper consideration is Japan. Will Japanese China be more or less industrialized then OTL China? I'd wager less, since to my knowledge the Japanese ultimately intended it to be a settler colony, and thus would've massively depopulated the locals.
I don't think draining the Mediterranean would've done wonders for the environment.
Myth. The Nazis demonstrated no active support for Atlantropa, and arguably less than post-war Europe. It's certainly not inconsistent with Nazi ideology, but it's so insane, impractical, and damaging to local economies that I'm not sure why you would ever put it into action, especially when you've suddenly acquired all these Reichkommisariats in the east.
That said, I'm not sure what the effects of Atlantropa would've been outside of the Med.
they were highly anti-science
Oversimplification. They were certainly hostile towards "intellectualism" (meaning thought that does not have clearly applicable practice value) and "jewish science", but certainly not science as a whole. As their top of the line general engineering, horrific medical experiments, and rocketry demonstrates, Nazis were not uniformly anti-science if they believed it would glorify the Volk.
They certainly purged their educational system, deemed intellectuals suspicious, and pushed some fucking whacky theories, but the exact same could be said of the soviets, who purged almost anyone with a modicum of technical competence in the 30s, constantly suspected intellectuals of being secret Bourgeoise, and pushed ideas like Lamarkian evolution in the name of ideology. And yet, they managed to develop the nuke very quickly (albeit with extensive infiltration), and some technology far in advance of the US in the space race.
If the GGR is in a similar situation, they have the benefits that they have the scientific institutions and traditions of all of Western Europe behind them as additional support (albeit in a depleted and purged form), institutions which have always been stronger en their Russian counterparts
I've said it before and I'll say it again: Nazi Europe would be a continent-wide Khmer Rouge. There's not going to be normality in Nazi Europe in the long term; that was all to keep the masses on board. It would quickly become a surrealist hellscape right out of Pink Floyd's worst "The Wall" acid trip.
Has anyone ever done a real timeline on this? I often wonder to what extent the Nazis would've impressed some kind of pseudo-Evolian Nietzchean "New Man" upon the Germans. The Hotler Youth will certainly make society rather different as time progresses, but how different?