Every country in the world would be an empire like the US if they only could. Its a matter of opportunity not motivation.
The bigger issue is what would China do with all that power? We know what the US does with it and I don't think a world lead by China would be as nice a place as a world run by America.
It depends on what you want. Me, I want a world with democracy and due process.
I don't see anything like that eminating from China and I doubt I ever will.