The class divisions are artificial because all persons are meant to be equal under the law.

Robbing is what literally happens when you're forced to pay for things you object to. If you refuse to pay, goons will come around with guns, take your property, and throw you in a cage.

The income tax is barbaric. It violates the NAP 100%. If the government needs to pay for public functions, I'm sure they can find a way without aggressing against non-violent people.

Flat tax systems are highly regressive in that the percentage of overall income/wealth paid by each individual becomes less and less the richer someone is.

The person with more wealth is likely to spend more and thus pay more in tax. That's how it works with the income tax. If all the rates of taxation were the same, people who earn more would already pay more due to the nature of it being a percentage. What we do now is really punish the hell out of these people. They don't just pay more in tax, the regressive rate increases. It ends up doing nothing more than taxing productivity and encouraging people not to earn more because the government would just take it away.