Table D is the table which Sweeney climbs on top of during Epiphany, so that is a GREAT view there. My seat in A3 was perfect to see Sweeney's entrance at the top of act one. I think the last seat I had was pretty good, but by then I knew the show pretty well and could follow the actors wherever they went. Had some good beggar woman action in that seat.
As far as bad seats, I don't think A3 was bad at all. Nothing I really couldn't see, as the theatre is so small that you could see an actor's expression from across the room. I would say maybe don't sit at the back of any of the tables unless you don't want much interaction. I did have to twist a lot in D2, but I honestly didn't notice it too much and there's ample room since they are tables, after all, and you're not packed in too tightly unless everyone has their purses or bags next to them (you could easily stuff yours under your seat, since they can't be on the tables). D2 was also a great seat to see all the bloody effects and possibly get sprayed! Don't wear nice clothes if you sit in one of those seats in the very center.