I don't know why you want to move the catapult to the deck, there's a reason why most navies had them amidships. USN practice kicked it to the fantail because of a lack of priority for it, in part because not only did we have carriers fairly early on, but some pretty large ones (other than escort carriers and the Independence/Saipan class emergency programs we never had a carrier smaller than Langley and Ranger). The whole point of trunked funnels is that you can consolidate the superstructure for a better protection scheme and/or firing arcs - in fact, on that note, you can rearrange the superstructure on HMNKS Grizzly so that the X and Y turrets are on the same deck (not necessary, but it does keep the topweight down if you want).
Almost everything in naval warship engineering is done for a purpose, and so far you've been pretty good at it, but I'm struggling to find the purpose here.
(drawings done at 3AM and prior to coffee. I DID say "work in progress" after all)