Some people live in a scary world. I would think it's quite stupid to be worried about this when the worst that could happen is missing a flight, which would not happen anyway if you pay attention to your surroundings.
Have you looked up crime rates in airports or what gives you this idea that it's a dangerous place? Unless you're digging up dirt on Putin and flying through Russia or some outlier situation like this, nothing is going to happen.
It's not a crime when the authorities do it, sadly. I've seen plenty of anecdotes here and elsewhere of people being detained without access to legal representation and without even being informed of what they've supposedly done wrong. If you're denied entry to a country then you have no right of appeal or anything.
The danger factor needs to be weighted between probability of the event and severity of the event. The probability of the things you describe are near zero.
