As Japan I always build an IC in the East Indies turn 2 regardless of setup. East Indies can reach Egypt, India, Australia, Persia and other parts of Africa while facing little threat from anyone. After turn 3 or 4 you’re ready for an India IC and can start pumping 7 units toward caucasus.
As for the Pacific theatre. A smart US player will send a large fleet off the coast of Alaska with supporting bombers in Alaska as well as 3 or 4 counterattacking subs off San Francisco. If Japan strikes their navy the rest will be destroyed with sneak attacks and bombers. The US can keep this up until there are no boats left and then an invasion force can move in. Part of this allied strategy invloves the UK going all out in the Atlantic because it’ll be awhile before the US can help BUT not letting Japan take over the world will be worth it in the long run. In '42 Japan has to buy at least a sub and destroyer to go with two more transports. The US navy is very strong to start '42 plus you may not attack the carrier, fighter, destroyer in Pearl Harbour.