I don't think it really handles any different than the longtail without the trailer or a regular bike with the trailer. I mean, it's long and ungainly, but it's not bad. I don't have any overpasses to go over, though. Just pretty much straight streets although I do ride on a sidewalk for about 10 meters at one point. And I take it off road for about 20 meters in a couple places (sans child). 90 degree turns feel the same on the longail with or without the trailer (challenging!). I too, am a woman who rides in dress clothes and a wool coat, so it's really not a big deal.
When you say pedestrian overpass do you mean those really tight corkscrew ones? or a slope, followed by 90 degree turn, then over? I'd take it on the latter but not the former.
One thing is that you can actually attach the burley with the newer attachment piece just as you would on a regular bike. I've seen people make these custom hitches on the back of an xtracycle, but it's not necessary and make it a foot longer. Just attach it at the rear hub - there's probably enough room.