VAT is a great alternative to a US style sales tax, but it is still regressive and UBI + regressive taxation seems like a pretty terrible combination.

Not if the UBI is tied to the cost of living index. Essentially, this means the UBI will be immune to the regression of the VAT.

Nonsense. Assuming the government intends to run something vaguely resembling a balanced budget, tax receipts (plus inflation away of govt debt) has to broadly, in the long term, equal money paid out (UBI + lots of other stuff). Which means (1) the government has to make up the portion of income tax revenues lost from high earners that spend relatively little by ensuring sales tax is sufficiently high to get the money back from lower earners that consume most of their monthly wage, and (2) every time the government puts the UBI up, they have to put taxes up [in the near future]

The problem is that UBI only works if it's redistributive. If you don't change the income distribution, the distribution of goods and services doesn't change. It seems to me like cost of living UBI + regressive taxation would just cause inflation with the UBI always lagging behind the newly higher costs.

Basically the point is that a VAT with a UBI tied to inflation WOULD be redistributive. It effectively nullifies the regressive portion of a VAT and ties the UBI to the overall productivity and cost of doing business of the nation.

We need to return to a wealth-oriented tax. Neither income tax nor VAT are taxes on wealth.

But even as someone without a lot to worry about, I can't think of a fair way to tax wealth outside of land taxes, which would greatly disrupt the economy.

The estate tax is one mechanism we have now to tax wealth.

The estate tax is bullet-hole ridden, unfortunately. Overall the US tax system is a mess.

once a lifetime taxable events are prone to huge swings in revenue, not to mention all the schemes to evade.

I would take the cost/benefit of a combination UBI and VAT over a wealth/income tax with current social safety net any day and twice on Sunday.

The problem with VAT is that it's a tax on consumption, not a tax on the accumulation of wealth. It's incongruous with the goals of UBI.

A wealth tax and an income tax are two different things.

Yes, I understand that but a VAT need not be out of step with the goals of a UBI if the UBI is protected from the regression of a VAT by scaling it with the cost of living.