My opinions in summary:
–You need a factory on the mainland. It’s debatable where, but against a competent Allied player you’ll need the boots on the ground.
–You’ll need a lot more TRs. Time is your enemy and having more TRs means delivering more combat power where you need it faster
–I favor a J3 attack. Spend 2 turns pounding on the Chinese with all of your air and getting troops and TRs in position to take everything you need within 2 turns of the DoW on the Allies.
–Try and keep your fleet massed. None of the Allies has the slightest chance against the full weight of metal that Japan can throw around. Granted you’ll likely have to spread out a little to accomplish everything you need, but try and mass up agains ASAP.
–Keep Truk and Japan garrisoned with fighters/tac. As long as you do this and have minimal infantry on the ground they will be EXTREMELY hard to take due to the Scramble rules.
–The primary goal if this strategy is the complete destruction of China with minimal losses and then a heavy focus on India. You only need to fend off the US and Anzac - you dont not need to decisively engage them. PI must fall on J3 to remove the US presence and to get the naval base, but beyond that you dont need to fight them unless they expose themselves to a favorable trade.