Could Japan have won if they lost?

We are in agreement with a slight variation on your last. By way of clarification the energy and immediate warfare efforts were focused on the central Pacific. You are correct, in the meantime, they were designing plans for the eventual invasion of Japan. We are in agreement again: it was Naval aviation, the Marine Corp. and the submarine force that won the war in the pacific. Of the three, subs probably played the biggest role. Although it would make for interesting conversation to rank the three in order of importance.

On an unrelated topic is there a thread debating the use of the bomb?

Oh, it is true bombing missions were conducted from Saipan and latter Okinawa AND the American carriers did indeed strike targets on the Japanese mainland, routinely. They may have started in late 44 but certainly, with great frequency in 45.

In fact, I think, the last casualty of the war was a navy fighter pilot shot down over Japan.

And it is also true that P-51 aircraft equipment with drop tanks flew for captured Islands on missions over Japan. There may have been other land based fighters to also make the run. The P-38 maybe? I can not remember. However, by January 45 the carriers had run out of targets and often hit the Japanese mainland land.