The whole point of my post is that progressive taxation is a question of which individuals pay what, not whether money stays with individuals or goes to the government. You appear to be caught up in the framing of political rhetoric.
By introducing variability of how much the government takes total it adds another question that is being used to persistently distract from the question of progressivity. When people say "the wealthy should bear a larger portion of the burden" a typical response is "we should be spending less on government!" – which is no response at all, just a distraction.
You said: "The notion that taxation should be predicated on whether the government or the person can 'better use' the person's money is damn scary." – which is EXACTLY what I was pointedly NOT asking. The degree of progressivity in a system does not determine whether a person or the government has the person's money, but WHICH people have how much money.
I can accept theoretically that you can separate the progressive structure of the federal income tax from spending decisions but in reality it is pretty hard to solve our budget problems by simply taxing the 'rich'--at least if you use the $250,000 figure that is most commonly used.
Here is a nice calculator you can use to see the difficulty: http://splitwise.com/taxes/
You keep giving these pundit talking points – the talking points of pundits have been rehashed enough, we shouldn't be using them here, it's not a productive form of discussion. Are we men or are we pundits? I, sir, am a man! ;)