Good ideas, Strategiclayabout. But what ist your intention?
Is it to counter the "anti-USA diplomacy strategy" or is it to balance Japan vs. China?
If it's the first case, it's the wrong way I think. Because for me the "anti-USA diplomacy strategy" is gamey and should be deactivated. No major nation should be able to influence another major nation by diplomacy - regardless whether allied or hostile. The (Axis-) players can "control" the US-mobilization by their aggressiveness. And nothing else.
If it's the second case, there is no need to rise american mibilization in response to japanese success in China. Because when Japan decides to conquer China, it will do so but it costs them a lot MPP which they need for their navy.
If you believe that Japans way in China is too easy, lets discuss about it (I don't think so) and manage the things between Japan and China directly.