The article misses the boat though. We pay about $400B a year in interest cost at an average rate of 2% with a 6y average maturity.
I am not sure the article missed the boat. The article doesn't give solutions, it just says there is a mess and gives some numbers. Unless you are saying that the article says that there is a mess, and there really isn't a mess; which could be true based on numbers such as yours.
I have been hearing more and more about this "economic time bomb" that Obama is leaving. But as I read more and more regarding analyses such as yours and elsewhere, I start to question just how much of an economic mess it really is. Just showing raw numbers is difficult in making any rational decision. Showing proportions would be a better way of determining if there is really a problem or not.
For instance, I have really got a hold of the P/E (or PE10) as a measure of value for the stock market. This proportion removes all inflation (which can be manipulated) and other single values to create something historically to compare. Other proportions I follow are: silver to gold ratio, S&P to gold, property value to income, etc...
So if I can find a good Debt to X ratio for historical comparison I will interested in studying that.