That's why it returns the interest to the Treasury.
the expansion of the balance sheet isnt a good thing, fractional reserve banking is our undoing
I agree with you 100%. We do not need a central bank; it was created solely to enable the government to fund itself without resorting to tax increases.
I do disagree with your interpretation of the Wikipedia article. The Fed does not take a profit of 6% on the entire money supply. At the current supply of money [M1], 6% would be $164.5 billion.
I will go re reread the monster from Jekyll Island to check on this, but I do believe it does pull 6 percent on the M1