"From what I've seen, it would be absolutely GREAT for everyone, that's what scares me."
Not everyone. There are some losers under the FairTax. These groups come to mind.
1. illegal immigrants - they move from a tax preferenced position to a tax disadvantaged one.
2. Those who have figured out a way to game the current system and pay disproportionately less taxes as a result.
3. Foreign producers - they have been given an advantage over US producers in the global economy - and globalization is a huge force that is sweeping across the planet.
4. Tax preparers and other professionals who make their living helping Americans navigate the incredibly complex system.
5. Lobbyists on K street - they make HUGE $$$ manipulating the Code.
Those are the ones that come to mind off the top of my head.
Other losers
Insurance companies who sell the tax-advantage of life insurance and annuities.
Municipal bond owners.
Estate planning attorneys.