I've run my business out of my home since 1986. You're really barking up the wrong tree here. Your concern is misplaced- it's really a small factor in the big picture. The IRS is way more dangerous, and the concept of taxing income itself is more an instrument of control than revenue collection. (Check my home page for a few interesting quotes on that subject.)
Once the Federal government is organized around collecting taxes on your sales receipts, what makes you think that the same IRS personnel won't be as aggressively dedicated to assuring that they get their cut?
You've got the picture - but understand that you're being attacked by a bunch of the Status Quo Lovers (aka SQLs or Squirrels) who have no tax plan to present and whose only interest is in trying to defeat the FairTax no matter what it might take.
Several of them have shown themselves clearly to be liberals and they don't give a damn about most of the country greatly benefitting from the FairTax.
Just ask one to present an alternate tax plan that is real ... and be careful for Nightie since he hypes a theoretical Flat Tax which is completely undefined and can be altered at the drop of a debating point. We call it the Nightmare Tax since it isn't real.
If you can get any of them to present their alternate plan, have them present the legislation that implements it.