At this point the German Civil War is basically a case of wanting a certain outcome (the big geopolitical eruption you mention), and then tweaking the plot to fit that.
The whole Africa plot is another can of worms since...none of the present Rks make sense.
Worth noting that the civil war doesn't matter that much after it's over...because despite the massive destruction it must have caused, Germany instantly bounces back to being a world power. It matters for all the opposition groups in Eastern Europe, Africa etc. since they can suddenly project an otherwise implausible amount of power (personally I also think that at present TNO overestimates how powerful partisans would be, but that's another matter). But it might as well not have happened for the narrative of say Bormann or Speer. At the moment there's a big disconnect.
If one wants to write a German civil war story, I'd personally scrap the part about Hitler appointing a successor (and Göring is either dead or he lost his status as a successor because Hitler's faith in him diminished after a health scare that put him out of commission for a while) and use the scenario akin to the one outlined by
@Tanaka did nothing wrong here.
I think the question here is that with all the reworks and removal of existing plot lines, at what point does TNO stops being TNO, and instead being 'WI Axis won WW2 TL number 236'?
Perhaps Kaiserreich have it much easier in that regard, due to WW1 ATLs not being as common, meaning that as long as you keep a victorious German Empire around, even with the removal of iconic elements like the AOG controlled Southern China , La Plata, Genghis Khan II's new Mongol Empire, Lawrence of Britannia, President Curtis avoiding the Second US Civil War, President Kerensky's assassination throwing Russia into a political free-for-all, etc, the KR TL is still recognisably unique... Though I would argue that if syndicalism as the dominate far-left ideology or the continued existence of the Entente operating in exile gets removed, that WOULD be a bridge too far in making Kaiserreich no longer Kaiserreich.
For TNO, however.... Lets be honest, 'Nazis won WW2' ATLs are dime-a-dozen, to the point of being THE default alternate history TL in popular culture, right alongside 'If the Confederates won the American Civil War'. Meaning that in order for TNO to be recognisably unique, it NEEDS to maintain its own niche, to make it different from say... "The Anglo/American – Nazi War", "Fatherland", "The Man in the High Castle", "Wolfenstein", "Thousand Week Reich", etc.
I would argue that at its core, TNO's niche would be,
'If the Axis powers were able to inexplicably maintain the same lucky strike that in OTL, enabled them to defeat France in 6 weeks, make as much headway against the Soviets as they did during Operation Babarosa, and for Japan to overrun Singapore and the Philippines with relative ease... But for reality to ensue when said plot armor suddenly wear off the moment they won WW2, resulting in their regimes getting slowly crushed under the weight of their own inherent issues that prevented them from winning WW2 in OTL'.
Hence, it can be argued that even with Atlantropa and the German Civil War removed, as long as the victorious Axis powers still suffer from the weight of their own self-inflicted problems, TNO with all the 'unrealistic' elements removed will still be TNO... However, at the moment, I feel that a TNO without the German Civil War might as well be a Kaiserreich without syndicalism... Or even a Kaiserreich in which instead of falling to a leftist revolution, Britain became a fascist republic.... With it being so removed from the original material that you might as well create your own TL instead of reworking the existing one.
But I guess we will wait and see if this rework will actually be carried out, and if the devs can pull this off...