The shoes thing - if you are exiting on to tarmac, yes, you want shoes that are not going to fly off. But if you are exiting into water, you need to ditch the shoes, especially guys who wear the big heavy lace-up DM boots or similar. I have swum in shoes, and it is very difficult (and these were running shoes, not big heavy boots), they drag you down. If you are exiting the aircraft into water, the last thing you want is big boots on. I guess the idea compromise would be shoes that cover your feet, but that can be kicked off very easily (you know, like your mother told you never to do with your school shoes!) if needed.

If you wanted to be prepared, your phone, wallet, keys and passport should be in some sort of waterproof bag (ziplock idea) otherwise some of them will be useless if there is a water landing.

I always fly with my own pashmina, but if you don't, you may want to keep that in flight blanket handy in case of an emergency - it can cover your head from debris, can shield your hands if you have to move something sharp or hot, and can be used to aid someone else in a water rescue, as well as give warmth once out if it remains dry (no matter how warm ambient temperature is, shock is bound to set in).

I also always have a water bottle in the seat back pocket that I would grab and bring with in an emergency - being able to get ash / soot / dirt off your face so that you can see, as well as being able to quell burning of the throat from acrid smoke is pretty important too.