I agree with IL above re maps. The 1936 map I have is just awesome. Though I can understand you’d want to make changes to cater to your game, I would agree that adopting the 1936 map would be a better way to go to get larger support here.
Also, one way you could alleviate so many changes would be to just sit down and talk about what you want. By that I mean, when you look at a single turn of your game, what is the scope? Is it a single month? Six months? Point being, the areas being too small for you (using your post on the Pacific being too small) and greatly be altered by what you want a turn to be. If a turn is one month, for example, ships from the US should more than be able to reach Australia within a single turn based on how long it would take a ship in real life to travel the distance.
What I mean is, if you want the naval/air war in the Pacific to last longer, or whatever your goal may be, maybe find an alternative to changing the map so much. I’ve thought about that too, and one thing I’ve toyed with would be ships/planes having to “search” for each other. There could be a dice roll where maybe you just couldn’t find the enemy ships, etc.
With that said, that also changes based on turn length. If a turn represents a month, it would be unrealistic to say on a single dice roll that no action occurred that month because they couldn’t find each other.
Just trying to think of ways where you won’t have to alter maps so much! :-)