Kingdom crown laws only apply to their specific kingdoms. So High Crown Authority in France won't apply to de-jure land in Burgundy. You need all your kingdoms to have High Crown Authority, or have high crown authority in your de-jure Empire.
OK, maybe not a hissyfit.
Still, saying that Germany lasts longer under the OP is not impossible is like saying Sealion isn't impossible. It just takes a whole lot of handwavium to accomplish.
He's saying your proposal for the Germans to survive is something out of a video-game. The entire crux of the argument is that everything goes right for Germany magically and everything goes wrong for the Allies.
Basically you're turning Germany into Draka-lite.
Getting into the interior of Anatolia is a little wankish as Athens was primarily a naval power, so I think they could get control of the coasts but beyond that? I doubt it.
Plus I don't think they could get a toe hold into Italy without first dealing with Syracuse. And the area across the...