This is a potentially very serious infringement of rights, particularly given that the TSA doesn't give any firm guideline as to what constitutes suspicious behaviour or who is "deemed" a "security risk".
For example, if I take a photograph at a US airport, which is frowned on by the TSA/FAA (although neither has ever declared to be illegal/forbidden in writing), I could conceivably have my licence revoked.
The constitutionality of such a provision would probably be successfully challenged, but before it introduces such regulations, the TSA would need to set out in writing what it will regard as suspicious - and explain the reasons for its suspicions.
This kind of heavy handedness not only goes beyond security, but it is actually very damaging to security, because it is done without thinking and as a result, alienates those who should be its allies in ensuring security.