The design was weird in that she was meant to be a stand-alone raider, so came equipped with a relatively large gun armament, 16 x 6in
We don't know what Graf Zeppelin was intended to be. German warsip design had fallen into confusion at that point. Just before the war, the head of the Fleet Dept wrote a memo noting he couldn't find any mission specified for his latest heavy cruisers and battleships.
GZ's gun armament was unique--twin casemate mounts. She was initially to carry eight guns in single mounts, but someone suggested saving weight and space by adopting twin mounts. Great idea, I suppose, but it got mixed up somehow and they simply doubled the number of guns. Not much weight-savings there. But the good news is that they forgot to provide ammunition for the new guns or berthing for the added crewmen.
Given the constant propulsion problems the Germans experienced with nearly all their surface warships, I'm very far from convinced that the GZ would have made 35 knots.
GZ combined Brown-Boveri turbines with La Mont boilers, just like Prinz Eugen. What could go wrong?
They had also catapult issues that were not fixed. It is said they sent them to Italian Aquila, another ill fated CV tough if Italy could resist one more year it might have got operational.
The Germans seem to have been happy with their flight deck gear. The stuff they sent to Italy had been for GZ's sistership.
The catapult system was a horror, and since ALL launches were meant to be by catapult, there was a serious problem in the offing. They were so committed to catapults that they didn't bother to set them flush with the flight deck. Why they did this is truly a mystery. They certainly knew how to set them even with the deck; in fact, Bismarck's catapult was not above deck level, as I recall. Can you imagine attempting a rolling take-off when you have two mounds, maybe a foot high, spaced more closely than the wingtips of your 109, at the front edge of the flight deck? If you're in a Fi-167, no problem, the plane could take off from a postage stamp. But the fighters and Stukas...yikes. I don't think it would be long before the Germans either reset the catapults at deck level or yanked them off completely. I could go on about the catapult trolley system, but I'll spare you. As for the landing equipment, the Americans inspected it and declared it inefficient and unsafe.