Who cares what oil is traded in. It is the oil that has the value. Not the currency. Next, apparently there is nothing but bullshit to be found on the internet on the matter. They say that Japan owns 1.1 trillion of the U.S.'s ass. That might be believable. But as far as I looked, it said that China owns 786 billion of the U.S.'s ass. I find that impossible to believe. Every single year our trade imbalance with China ranges anywhere from 257 billion to 419 billion. That is minus the value of what they import from us. That has been going on for at least the last 20 years. That debt doesn't go anywhere. It just adds up.
Let's take the best case scenario and say that every year our trade imbalance with China has only been 257 billion per year. Which means 257 billion deeper in debt to them. In the past 20 years (at least) our debt to China must be around 5.14 trillion. On another note, there is talk now and then about possible conflict with China. They could put us in a hurt by just demanding payment for what we owe them. Our likely response to that would simply to add another 5.14 trillion to our national debt. But with the U.S. already being so far in debt, our currency is already basically worthless anyway. So what could it hurt.
Next, you are wrong about what makes Chinese exports to the U.S. cheaper. It isn't what they "do to stabilize their currency." It is the fact that on average, American workers make around $29.32 per hour. Though it was difficult to find, I found out that the average hourly wage of a Chinese worker is $3.60 per hour. Basically, Chinese workers are our wage slaves. That is impossible for an American worker to compete with. But those who sell Chinese products in the U.S. are probably shitting gold. But you would probably say that taxing the rich is bad.