I agree that the Kurile Islands and Sakhalin would be Japanese; if not before the Global War, then certainly afterwards.
I was thinking that the Japanese might have just sold Taiwan to K.A. to pay off their debts to the company, but I agree that a purchased election is more K.A.'s style.
I assumed from the English name that Midway was a British possession before the Global War. It's possible, though, that it was renamed Midway by the Mexicans after they took it in 1942, and they kept calling it that after losing it to the Japanese. Either way, it's an interesting coincidence that it received the same name in both histories. Ditto the Marshalls.
I don't know about the Philippines being a Japanese possession. The first time Sobel mentions it in 1926 it's an independent republic with a president as chief executive. I figure the Philippines either broke away from Spain during or immediately after the Trans-Oceanic War (with British help), or during the Bloody Eighties while Spain was in chaos.
Sobel makes it sound as though Japan and China were allies during the Global War against the Germans and the Mexicans/Siberians, though I suppose there could have been a three (or four) way war going on there.