re: value added tax
While generally a wealthy person will pay more "sales-type" taxes anyway, you may still run into the issue of how to insulate the truly poor from this kind of tax. You can make things like food staples tax free (like they are now from sales tax) and maybe some other items. If you stick to making certain essentials tax free, you'll be okay.
But if you arrive at a point where someone has to say, "a rich person must pay the tax on this item, but a poor person does not," then there has to be a reliable way of identifying them at the cash register. Not only would this involve paperwork and identifying things like income again, but the spectre of a "Poverty ID" raises its ugly head.