On paper, I think it sounds like a great idea for all the reasons you mentioned. But in practice? It couldn’t ever replace the income tax, and I’m not sure if the general public will tolerate the addition of another new tax on top of all the other ones we already pay, especially since it is, as you point out, a regressive form of taxation.
As far as the debt/deficit goes, we’re in a tight spot. Conservatives won’t tolerate large cuts to military spending or massive tax hikes. Progressives won’t tolerate large cuts to welfare spending and are constantly asking for even more money to fund even more programs. I’m not sure where you go from there. I feel like there isn’t a good starting point for a compromise when both sides are so far apart from each other.