The way the Fair Tax is configured it eliminates all your concerns. Does that mean we can control or trust politicians in the future? No, but it does mean we can start with a clean slate and keep a sharp eye on them to try to prevent it.
All the social engineering you fear is happening right now and choking our economy and free society. Why not start over?
Why add a new set of social engineering tools. Just because you like those more than the current ones?