Like, I'm on a plane. I don't want to watch Toy Story when I can do that at home, I want to see what the pilots see. And that way every seat has technically a window to look out of.
Possibly. I do recall a commercial aircraft crashing when a bunch of people ran to the back of the aircraft because an alligator got loose. Something to that effect anyhow. Pretty sure was in Africa. Can't find a source for that.
Overall large commercial are pretty stable. Don't think you could effect c of g much laterally but possibly longitudinally you could.