I agree with you on the obstacles facing China to becoming a superpower which are far greater than others imagine. Working there, you see how inefficiently resource allocation has been for state owned enterprises which in turn have propped up stock prices and real estate. How they're able to deal with any bust politically is what scares me.
The government is already largely hated/strongly disliked in many quarters (there are many who have long memories not to mention the obvious and very visible corruption). It bears mention that that China liberalized not because they wanted to, but because they had no choice given how poor their people were. When the bust happens, the increased civil unrest and the government's overriding resolve to maintain power will be a volatile combination - one that Japan didn't have to deal with.
I also agree that the parallel of Japan seems more relevant to China than the US. China's non performing assets in their banking sector has likely grown quite significantly with the push for lending in the last year. The average Chinese aren't stupid either - which makes it a potential catastrophe if certain world leaders get their wish that the RMB is allowed to float. Capital will rush out of China and its domestic banks causing a financial crisis and ironically potentially a RMB that is worth substantially less than it is today.