Kits mentioned above that do exist and listed at Scalehobbyist.com:
Lindberg's 1/48 Jenny is available
Italian Warships: 1/350 BB Roma (Trumpie, pretty new), 1/350 Hobby Boss cruiser Pola is out there but is not well reviewed and hence cheap; 1/700 - BBs Vittorio Veneto; Littorio - both Trumpie
1/350 Scharnhorst - DML's version out two years ago - 1100 parts
1350 WWI - Dreadnought (Zvezda & Trumpie): Trumpie has a 1/350 WWII Queen Elizabeth and a 1/700 WWI version of the same ship: we can hope it will come out in 350 as did their Warspite. The ICM Konig class BBs are still widely available - it's a difficult kit as I can attest. Zvezda's new Svestapol has gotten very good reviews: like Dreadnought it's a relatively simple ship with no flak or radar and thuus has a low part count in the 300 area.
(Pre-WWI vessels are represented by some terrific kits. Hasegawa's 1/350 Mikasa looks very good and certainly deserves a build. Bronco's Chinese warships are very sweet models: I have a BB and cruiser Chih Yuen - I believe both come with complete PE. The cruiser is a lovely vessel and will get a full hull build from me. Emden pops up on eBay (I have it) regularly and is still supported with PE. I can't say about Encore's 225 Olympia other than it's old: as I can attest the Encore Oregon is not for the faint of heart.)
WWII Brit Carrier: no 1/350 but the 1/400 Illustrious (in WWII configuration) has been reissued by Heller and is considered one of their better effort. (Wonder if it could be made into Victorious? I was very bummed by I found out the Airfix 1/600 Victorious was Cold War) I'll refer this one to Model Warship because I too would like a WWII RN CV.
There is no Enterprise. I can't see doing surgery on Wasp - they were very different ships. You're in luck with Saratoga.
No doubt looking at resin kits makes you wish. But for me that's where it's going to stay. I've been moving to water based paints like Vallejo and Golden because it's a delight to do without the solvents. My experience with resin is limited but anything that requires heavy duty masks, soaks in tire cleaner and must be glued with CA is not going to be for yours truly.
I'm building 1/700 DDs now. The downside is pretty obvious. But I also have finite display space and a 1/350 capital ship will fill it fast. There's something else nice about 1/700 and 1/600: they either come waterline or are pretty easy to convert. Even though I don't build dios (I'll get around to that when I build decent models to put them in) I like waterline anyway. You just don't think of a ship at sea as full hull which makes weathering really abstract. (Subs are an exception here.) I've decided that in future I will do any full hull ships with shading, filters, modulation etc to give the color some depth but no weathering at all. A lot of fine ship modelers do that regularly and it would be a great challenge just to make a really clean build. A waterline almost cries for heavy weathering. It's odd in my view that so many ship modellers are restrained with weathering when a wartime ship is probably getting worked pretty hard and they live in salt water. Some ships could be validly weathered as enthusiastically as a tank.
Eric