Going to respond just Re: #1. The unreasonable search argument has little to do with the right to travel argument.
It is about the right to decide when a body is restrictable/invadable. Even if I had no "right to air travel", I have a right not to be subject to unreasonable searches and seizures.
Yes, you can search me if there is one of several public purposes (e.g. public safety) justifying it. But your search must still be reasonable. And reasonable is more than just saying "people might die if we don't do it." Reasonable is establishing a relationship between the search and achievement of the goal to be achieved.
And the burden of proof -- and this is key, and almost always forgotten -- is ON THE GOVT AGENT SEEKING TO SEARCH. The burden is NOT on the person being searched.
And the GOVT AGENT SEEKING TO SEARCH is supposed to satisfy a significant part of that burden of proof BEFORE the search is authorized. That is why "having a search warrant" is the default.
And it is supposed to satisfy that burden of proof with respect to the individual being searched and the extent of the search. You don't get to get a search warrant against "all possible drug dealers" or "all possible terrorist" much less against "all citizens who fly."
The TSA engages in millions of searches each day. Millions of times that it fails to establish
with respect to the individual being searched that it believes it has just cause to believe that said individual is breaking
any law.
The state can *always* come up with a clear and present danger to justify use the police power. The 4th amendment is there because the founders believed that search of the individual demanded individual justification for search, not just a clear and present fear.
Terrorists may have weapons of mass destruction in their USA apartments. Drug dealers may be concealing their drugs in bodily cavities. Neither fact, however true it might be, gives the FBI or local law enforcement legitimate power to go door to door and search everyone's apartment. Neither fact, however true it might be, gives the FBI or BAT the power to stop everyone walking past a particular intersection in a particular town.
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)