I am not sure if I understand You. Let me expand my thoughts.
You seem to be convinced that the Fi-167 wouldn´t be part of any airwing. I would like to know what makes You sure about this detail? Fieseler signed contracts to deliver them but stopped production after the preproduction models because GRAF ZEPPELIN´s fitting out was halted in May 1940 when ca. 90% complete.
The Fi-167 was taken out of consideration in late 1942, not earlier. And that was with the hope expressed of getting GZ service ready by late 1943. I suggest that You encounter three years difference here. These three years make up for quite a difference.
What are You going to supplement the Fi-167 with when You continue along schedule with the fitting out of the carrier? The Ju-87C couldn´t lift off a torpedoe. The Ju-87D could but this plane isn´t aviable before 1942. In my mind one should replace the Ju-87 entirely with Fi-167. The latter may not have been that fast but assuming a Db-60E rated to 1.42 ata (using C3-fuel) instead of a Db-601N and the difference in speed between a Jumo-211J driven Ju-87E and a db-601E driven Fi-167 is simply not justifying the preference of the Junkers.
The Fi-167 had a longer range, could dive bomb, carry a torpedoe (or big bombs), had better handling and a larger general flight envelope.
It´s true, it´s an odd looking biplane but does it compare unfavourably with -say an Albacore, a Stuka, a Dauntless or a Barracuda?
My strictly personal opinion was that -had the fitting out been continued then GRAF ZEPPELIN would have been completed during winter 1940/41 with most of the year 1941 spent working up, isolating and deleting problems and create useful deck procedures. It´s not unreasonable to see her ready for action in late 1941 and by that time the Fi-167 is the mainstay of this carrier. I do think that experiences in the working up period would also be favourable to the Fi-167, guessing from it´s benign flying and gentle stall charckteristics.
It was the only plane not intended for catapult action and thus GZ could entirely operate it´s full airwing without breaking for replenishing the compressed air reservoire. This would probably have played a role in the decision making process, too. With the airwing centered around Ju-87 and Bf-109´s, only one would sooner or later get rid of the whole catapult system because it couldn´t provide enough power to support them all and what´s the point in having an installation sufficiant for 50%? That would make for a big improvement in allowing rolling take off but it´s still in the future by that time.
Regarding launches, my main concern is with the 109, (...)
The height of the catapult housing above the deck was not constant, so the hazard would vary.
the "obstacle" was to low to play any significant role as mentioned in my post above and the gentle slopes allowed to roll over them:
It requires about 20 deg roll to touch the rails with the wingtips. This is way to much to justify the term "obstacle". Contrast this with another, successfull carrier plane like the Fairy Swordfish:
You see that it´s wingtips may touch the flat runway with only about 18 deg roll factor but here it´s not assumed to be a problem. The larger anhedral of the wings in combination with larger struts allowed the clearence to the ground -or in this case the catapult rails. I don´t think this really becomes an objection for rolling take offs of either Bf-109T, Ju-87C or Fi-167 on board GRAF ZEPPELIN.
You can argue that a qualified pilot should not be troubled by such things; more reasonably, you can argue that the difficult task of carrier take-off was challenging enough without deliberately making things more difficult. The hazard of ship's motion comes increasingly into question for the carrier whose hull was improperly designed in the first place.
I do not agree that qualified pilots do not require or are grateful for additional directional evidence if pilot view is obstructed. In fact signaling over the side was also done in many cases during approach conditions of past and more recent carrier deck operations.
I do not know why GRAF ZEPPELIN´s hull is improperly designed. But perhaps You can expand more upon this?
btw-do You have Hadeler´s vintage edition of Kriegsschiffbau?