According to my last A1C test, I'm just as sour as I'm supposed to be! The thing is by the OP's conditions, acting from the spring 1942, the no Pearl Harbor attack ship has already sailed, so now you must try to make the most of what you got and hope for the best. None of the things I suggested are beyond Japan's ability and most were attempted later in the war. Further it can be argued that Japan's "make it too costly" strategy eventually did wring one concession, the retention of the Emperor. Keeping the 1st Carrier Air Fleet together offers the possibility of winning a "Midway" type battle, possibly two (say a "Coral Sea") which pushes back the US timeline by at least 6 months, perhaps a year. Historically we know how much Japan was willing to pay to survive, just how much we were willing or able to pay for victory was never fully tested.