In your scenario, I doubt that the blue-hair who has to blow up a plane or have her family killed is going to act just like she's on just another routine flight. That's where profiling behavior would have to be done. A few minutes of interrogation should identify that her behavior is a bit odd. But, if we think some TSA flunky is going to be able to do that, I think we're mistaken.
In my line of work, I fly a lot. I hardly know where I'm going to be going next, in fact, and fly at least twice a month. And I've observed that the security measures taken to secure air travel are just plain idiotic. They've secured NOTHING.
There is no end to the objects and substances that Muslim terrorists can bring on board an airplane and kill the passengers or wreck the thing. Our methods for screening for dangerous objects include only honesty (law-abiding, non-terrorists voluntarily give up certain items or substances for no good reason), X-rays for some checked baggage and all carry-ons (detects only SOME dangerous objects), metal detectors for passengers (detects only metal objects - does not detect ceramic blades, for instance), and very expensive explosives sniffer devices (detects only some specific types of explosive substances). NONE of those methods and NONE of the current methods would stop a Muslim terrorist from carrying out a slightly modified version of the most recent liquid/gel plot.
The only sane screening method is to target the population demographic that is responsible for 99.99% of terrorist acts. The only sane thing we're doing is deploying armed Air Marshals on some flights. But the policies under which Air Marshals must operate have reduced their effectiveness considerably.