Well, the ROC is the leftovers of China's gov. after the communist uprising. If the South would have won, and more of the country would have sided with the Confederacy, and the US government would have been run out of Washington and forced to hole up in New Hampshire or Maine, that would have been more comparable to Taiwan.
I guess we'll have to disagree on the China as a threat thing. I think nationalism is growing in China, and if you've ever interacted with grad students fresh out of China you realize the extent of the control of information by the Communist government. Yes, they have capitalized a good deal of the industry. But the government still controls the minds of the people. I am concerned with them trying to control all of Asia. That is not a good scenario for the Western world, the US included.