I have not flown within the US for some years and cannot comment on the security arrangements there. Here in the UK terrorism has, sadly, been a problem for many years. I routinely operate military helo's into civil airports. Every time I have gone, with my crew, into the terminal for a meal or whatever I have had to undergo the standard security checks (metal detector, and search when invariably it goes off) to get back to a gate for pick up to go back to my aircraft. I should add that we are all in blindingly obvious military flying kit and carrying military photo ID. This cuts no ice with the security people. However, we are treated politely, which has been my usual expeience with security in the UK whether operating or travelling as a "civilian".
Also, a high proportion of all pax are "frisked" as a matter of routine going through security here. I am not sure if this makes life any safer, it can't make it more risky and I don't get offended by it because everyone is treated the same way.
On the note of baggage matching to pax and screening of bags, I am afraid the Pan Am tragedy over Lockerbie taught us the hard way. I have seen bags offloaded here, causing missed slot times, because a pax had failed to show having checked their luggage. Which would you rather have, a late departure from the ramp, or an early arrival in the next world? I am sorry if this appears sharp but these are the unpleasant realities of the world we live in, there are some very bad people in the world who would murder hundreds without a second thought. I can live with a little inconvenience if it denies them that chance.
My only other comment would be that a good security system needs good people to make it work, rudeness by security staff does not enhance effectiveness. Proper selection and training, monitoring of performance and a decent salary would help a lot however.