We have two different situations:
1) China acting the way it is, well, it's hardly orthodox, but not impossible. History would have likely seen the Empress as a very eccentric character who faced innumerable obstacles for trying "radical" reforms in a very conservative-minded scenario. Basically a woman way ahead of her time, with all the problems that carries. Perth was very nice in his first post to err on the side of caution, but he'll certainly get the grip of things and start portraying how it would have not been so easy, though still not impossible, to successfully pass those kinds of reforms and survive the consequences.
In any case China is betting very high, and its success will be largely dependent in if the other nations try to call her bluff or not. So let's keep this IC, now shall we?
2) It would be nice if the GM made some mini-updates commenting on some situations going on (I can help with that). If the Emperor called one third of all the samurais in the country to send them far abroad to the "west", right after having coup'd the Shogun, well, he'd have a large rebellion in his hands.
Part of the problem is that Japan started with 600.000 soldiers, which makes one think of a professional standing army, instead of a potential force of feudal warriors that would only be completely mobilized in cases of invasion. The Shogun did not have such large force immediately under his command, and could certainly not do whatever he pleased with it, for it was largely autonomous.
The mini-updates would hint the player about this kind of thing, about worried advisers and unrest based on rumors of such kinds of plans. Then the player can decide if he really wants to go through with it and face the consequences, or not. And even then, he might roll several 6 and get the political ability to send such large force, giving the GM the task of determining the problems of logistics and unrest in California and the USA because of the "invasion".
The point is that the dices should be cast, and say if it goes or not. It is /very/ unlikely to succeed, but it is also very unlikely for him to get all 6s. Simply shutting down crazy ideas makes the game quite boring. Lets let strange things happen, even if they turn into major disasters.
