many of these people are foreigners, ie. visas, passport, cash/cards, etc... It is night and day difference between having your passport+visa available for immigration control and the alternative.
My ex once asked me what I would miss the most if my house burnt down. I immediately said it would be the documents. I would probably worry about this even after I got an American passport.
no. If everybody just rushed to the exit - it would bottle-necked and throughput would dramatically drop like it frequently happens in the known cases of club fires for example. Instead it dictates specific, much calmer, tempo: me/family alive and whole, neighbour alive and whole, bag with passport, lets move...
There's an interesting report on the A380 certification evacuation test[1] of ~870 people in 78 seconds. Granted, that was in a hanger with volunteers who knew it was going to come (but not when).
Serious fuselage damage might put enough exits out of commission to heavily bottleneck, though (although I think there's supposed to be some significant safety margin on those as well).
