"Exercise:

At 100% taxation you get zero income to treasury.
At 0% taxation you get zero income to treasury.

Since you are so wise in the ways of macroeconomics and know despite other evidence to the contrary that tax cuts always make for increased revenue, where exactly does the optimum tax rate lie?

We might as well make it that asap...... "

You could have zero taxes and still get revenue.
For instance churches can run off donations, so there is no reason a govt couldn't run on donations or other mechanisms. A zero tax govt would probably resemble what people normally associate with communism- real communism, not the glorious route of making huge oppressive Socialist state with idea that this will force a nation become communistic [because Socialism is obviously unstable and will evenually crash from it's own weight. And supposively from this disaster and ruin the flower of Communism was suppose to blossom.]

The closest any country came to a true communist state was America in it's early history. Though the US didn't have crazy idea of being anti-capitalistic and people being the property of the State. But from the beginning it had the idea that a small govt is the better govt and that any work for the govt was a duty rather than a career.