CO used to be the only airline I flew that never asked the exit row passengers about sitting there. However, for over a year now, they've asked on every flight that I've not been upgraded on.

As for whether the window plug gets tossed out or set inside on the seats, I've noticed it varies by airline and aircraft type. I've been on some airlines where the 733/735 safety cards showed the plug being placed on the seats. On others, they show it being turned around and thrown out.

And yes, I've seen two extremely obese passengers in the exit row, both of whom needed seat belt extenders, and the flight attendant said nothing about it. This was on a Chautauqua ERJ, and they were seated in 12B/C. I was in 12A and was very surprised the flight attendant didn't move them, because there was no way either one of them was getting through the window exit.