VS-LHRCSA,
I'm pretty surprised that people actually spit at check in agents (can't people like that be permanently banned?), but then cheaper air travel has opened up flying to the kind of undesirables who in the past would rarely if ever go near an airport.
I agree, the problem is a management issue, but having said that, in any customer service industry, aggressive or abusive people will be met from time to time. Just take a look at a cross section of the UK population, some people are really nice, and others are thugs. In a cutomer facing role, all of these types can be met. It sounds elitist (but isn't), that in the past most of such undesirable people couldn't afford to fly anywhere.
As for baggage, maybe pax should know more, but not everybody is a frequent flyer.
From the check in staff point of view, surely they need to just accept the fact that;
1. Some people will always 'try it on'.
2. Some people just don't know/care.
3. Some people on this planet are not very nice.
The very worst that can happen is for air crew to start assuming all pax are like the above, as it just isn't so.