Do evacuating pax really have to trample all over the door to get out?) Presumably this is the same for four-door 757s and 767s, and the A346 as well?
I believe that there is a slide attached to A310 OW
exit, but I imagine that watching a door fall onto the wing, bottom-hinged, and then seeing an evacuation slide overtake the door and inflate to the side would be quite a sight.
The four-door 757s and 767s are similar to the A310, but since there is no wing, the doors can rotate completely outside and the slide can inflate. See this picture: http://aviation-safety.net/pictures/displayphoto.php?id=990087&vnr=1&kind=E
The A346 OW
exit is just like the other doors, except that the slide goes down the wing (similar to the 330, 340, 747, 777 OW
And what about the small upper-deck doors on 741s and 742s? Do they have a slide?
They do. The door, someone could got into more details on this, basically rotates in, and then moves over like a sliding door, and then you have to manually release the evacuation slide.