It is purely inflationary of itself regarding any contracts that tie wages or purchases to any price index. Wage agreements, I should think, would be more directly affected, but we would have to see how exactly this would play out. (C'mon mate, that should go w/o saying.)
Of course, if enough people get sick of a 'fair' tax regime, it might become somewhat deflationary, as people go outside the regime and are forced to discount prices as a condition of doing business and not getting caught.
Go look up the definition of inflation. It is a purely monetary phenomenon, as Friedman and von Mises pointed out.
Sorry, that's still incorrect. Inflation is a monetary phenomenon. In other words, it's caused by the government printing too much money. That is the only cause of inflation; c.f. Friedman. The liberal theories that said otherwise were thoroughly discredited during the "stagflation" of the 1970's. Since inflation is caused only by monetary policy, it follows that other actions (such as a change in the tax code, or any given wage agreements or contracts), cannot and do not cause inflation. Thus inflation, or lack thereof, is a complete irrelevancy in discussions of the FairTax or any other tax proposal.