I've always been a believer in having a moving conveyor type buffet line--- you step on it--it moves you along at a decent speed and if you don't get what you want---tough-- get off, go to the back and ride down the line again.
Problem solved--no sampling this, that, agonizing over whether to try this or that--get it or miss out!! Or have a retired Drill Sgt.walking up an down the line--guarantee the line would move smoothly with no complaining and no jam ups.
Oh well, we can dream can't we??
Seriously, the cruise lines could do better in many cases when it comes to having omelet stations set in a certain area that does not back up the line but folks could help out too by being more aware that they are holding up the line by nit-picking through everything and acting like it's a million dollar decision on what to eat.
Re / elevators, I don't think some people can help but stand with their nose nearly touching the elevator doors when they are waiting--like they just don't expect that it's just maybe, remotely, possible that someone might be wanting to get off when the door opens. But you see the same thing at elevators ashore as you do on ships so it's not something unique to cruise ships.
I think too that if the buffet's crowded and when you eat, you should move on--you don't have to gobble down your food but should be aware there are others wanting to sit and eat too. I have no problem telling someone that they're welcome to sit with me/us when they are obviously walking around looking for somewhere to sit. You can meet some interesting folks that way.
And I have to agree with Katlady that respecting the culture and people of other countries is very important. To you, it may just be a speck of an island in an ocean but to the people who live there, it's their home and you're a visitor--conduct your self as such.;-) ;-)