I agree wholeheartedly with replacing every tax with a sales tax.  The other benefit you didn't mention, is that paying a sales tax with every purchase (especially if it was mandated to show on the receipt how much went to every taxing authority) would make people realize how much they really pay.  It would make them realize that nothing is free and make them quit voting for whoever promises them the most "free" stuff because they would realize how much they were paying.  If the sales tax replaced all taxes, (not just income tax), it would overall reduce the burden for small businesses.  As a small business owner, I know I pay several taxes, that the cost of figuring how much I owe and doing all of the paperwork, is higher than the tax itself.

On the other hand, I disagree vehemently with a land tax.  If you have a land tax, you never own your property.  You are just renting and can be evicted if you ever fail to pay your tax.  Property tax is as evil, probably more evil than the income tax.