No need for bouncers on every airline though... I once flew with a girl who to look at you'd think she couldn't hurt a fly. However, she was ex police special unit and also did a stint in the army.
Just for fun (and after a couple of bevvies I must admit
) on a nightstop we asked her to demonstrate on our captain after he'd given her some good-natured teasing on the flight over.
She had him on the floor and helpless in 3 seconds flat. He was 6 foot something and beefy as (bouncer type
) and she was about 5' 5" and nothing to her.... :P So looks can be deceiving!!
Jumbo, when a passenger is offloaded, the baggage MUST go too... I believe the practise came about after a lot of aircraft bombings back in the 80's (Lockerbie, anyone?) where passengers(terrorists) 'missed' the flight... now the nutters just bring the bag on and stay with it, but it's done to minimise the risk of the would-be bomber who just has to check a bag in and run... I believe it may even be law. Hope this helps explain it for you.