Thank you for responding. I'm glad we agreed in principle on #3. I'm afraid we'll have to disagree on the other points though:
1. The claim that spending / GDP is at WWII levels is simply wrong: please take a look at the link in my original comment.
2. 9% isn't nothing, agreed. It does, however, pay for: scientific and other research (mostly medical, then much smaller slice for general science, then a much much smaller slice for everything else); keeping national parks running smoothly; keeping planes in the air; shutting down financial scams; and other wonderful things like that. Like you said, it comes down to what we get for that spending. I think there's bound to be some waste here and there, but I rather like all these things our tax dollars are paying for. Oh, and funny you mention USAID - I rather like the idea of feeding starving children around the world too, with a triple whammy of moral impact, winning hearts and minds in other countries, and putting money into the pockets of US farmers. Would love to hear properly sourced arguments on why USAID is as terrible as you seem to think it is.
4. You forgot about the shareholders. Corporations mostly get taxed on profits, not revenues, so it's hard to see how consumers are part of the equation. (We're not talking about consumption taxes, which tend to be state level anyway.) And employees pay income tax - the only part that the corporation covers is the employer end of payroll taxes. Wikipedia has a nice breakdown and comparison: https://en.wikipedia.org/wiki/Payroll_tax
(Yay, thanks to whoever saved the parent post so my thumb exercise wasn't entirely wasted.)