Ok, now this is probably going to shock you, given that we are on dimetrically opposite sides of the political spectrum, but I agree with you about double taxation of money! It doesn't make any sense. Money should be taxed once only. Of course, the estate and capital gains taxes, and all the others about which this is said, are obviously not the only ones for which this is true. All money in our economy is taxed multiple times. Sales taxes are taxes on money that has already been taxed once (when it was earned as income). So really, you could make this argument about all taxes.
But, I agree with you that the tax system is too complicated and should be simplified. I favor eliminating all taxes except for the federal income tax, including sales, property, capital gains, estate, state income, local millages, etc., and instead raising the federal income tax by whatever amount would be necessary to compensate for the loss of revenue from all of the eliminated taxes. Eliminating sales taxes would be especially beneficial to the economy, as this would result in an across-the-board cut in prices thus encouraging spending (and wouldn't it be nice to be able to buy something without having to mentally do the arithmetic about how much it will cost...the price you see is actually the price you pay, wow!). The federal government of course would be required to make the appropriate revenue sharing arrangements with local and state governments to fund them, or it could be a chain system (federal funds state, state then funds local). Such arrangements are already in place though everywhere, it would just be a matter of increasing the funds being transferred.
As far as our beliefs about the proper role and scope of government in providing a social safety net, I'll just say that we'll have to agree to disagree on that point...
Your views, as you are well aware, are quite a bit to the right even of most of your own party.
Yes, the Laffer curve is correct, but I think that the point at which tax revenue starts to stifle economic growth is quite a bit higher than any of our current rates. Even most conservatives have now admitted that lower taxes do bring in less money for the government, not more, but they say well, that this is a good thing, not a bad thing.