Oh, I don't know if China will push it too far, they want to push back, yes, because they see themselves as the masters of the South China Sea, however the last thing they want and need is a war on the Korean peninsula. So they'll probably probe the wargames, probably with AGIs but I doubt they'd directly confront the US forces, just stage some wargames of their own.
Perhaps they might start pushing towards Taiwan, make the US shift its attention over there or even the Spratleys.
As people say, China will do what is right for China, no matter what allegiances they may hold with Kim. If Kim starts a war, China will not get involved unless the UN forces cross the DMZ and head for Pyongyang again. They have too much to lose from supporting an offensive against the US and its allies, but again, too much to lose from the destruction of the DPRK (including thousands of DPRK refugees crossing into China), so the status quo suits China fine...the only concern Beijing has is the stability of the Kim leadership and its monarchical sentiments, after all, if Kim Jong-ils appointed son dies shortly after Kim does, then what happens? Who takes charge? How much instability will there be in the interim between the death of the old leadership and the creation of the new? How will this affect China? Too many variables, and I don't think Beijing likes too many variables. Bad for business

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