Any real preparedness is bad for the attacking a/c IMO, & IJN can't afford to take losses in aircrew, with such a dismally low replacement rate.Shortly after a declaration of war, instead of before, would make it much less of a "sneak attack". I don't think you can conclude that the aircraft would have been slaughtered, though more casualties are quite possible.
No argument. OTOH, Nimitz (Kimmel?) is going to be without both his starting CVs (lost in the Battle of Oahu to a much better-prepared, & more experienced, Kido Butai). So he'll have to rely on his subs more, which means English might make small changes, like concentrating on Luzon Strait, or putting tankers on higher priority, earlier than OTL. If either happens (never mind both), Japan loses sooner...This sometimes does irritate me about certain AH explorations - the idea that a setback is going to make things better for the US than OTL. (It's often the US.) The torpedo issues aren't going to just go away, and so the first year or so is going to be poorly managed
I'm taking you to mean there's pressure on Nimitz (should I just say "CinCPac"?) to produce something like a victory. Okay, there's likely to be the stupid Doolittle Stunt, attacking Tokyo. There's a chance the Makin Raid still happens, with pernicious effects later.if things are rolling into the end of 1942, after six months of defeats for the US followed up by no apparent movement for another six months (and with the best estimates being that the US will only have more fleet carriers than Japan 36 months after ordering, that is to say in another two years - that being the ordering to commission time of the historical CV-12 Hornet...) - it's a hard thing to wait for a long time without any success.
Or the MC could adopt the F4U a bit sooner... Or the AAF could get P-38s in SWPA sooner... Or somebody in English's command could actually listen when his skippers complain the f*king Mark 14s/Mark 6s aren't working & fix them before September 1943.
See, it's really easy to screw up Japan's OTL outcomes without really trying...