Regarding mist in the cabin, this reminds me of a flight I was on in 1976 from then Leningrad to Moscow aboard a TU-104 -- the Soviet first commercial jet with a landing parachute which some little guy unhooked and collected at the end of the runway upon landing. It was repacked in the tail again before takeoff.
Anyway, back to the mist. Shortly after takeoff, from a rectangular hole in the middle of the cabin there appeared thick white clouds and the white knuckle passengers got even whiter. Some Russian women fainted from the so-called "smoke." Others had a hard time breating.
I asked what was going on and an FA told me, "Ah, I see they again put too much dry ice in front of the air conditioning fan." Otherwise, the flight was a little moist, but othewise uneventful.