Those two factors that place it at the heart of the global economy probably means it won't sacrifice its economic links in some wild power projection into the South China Sea.
I know that the relationships between England and Germany in the early 1900s and the U.S. and Japan in the 1920's and 1930's would be an indication that sometimes nations are willing to trade a bit of profit for a lot of power.
China never really had a lot of 'hard currency' in the past, living off their trade deficit with everyone else. The economic 'pull' that they have incurred by purchasing U.S. debt gives them a powerful new weapon... one I fear they plan to abuse.
A sleeping dragon is awaking- whether it is filled with 'terrible resolve' or 'piss and hot air' remains to be seen.