The main thing we should have asked was:
What hours do you do viewings?
One firm we used only worked until 6 which meant, in London at least, that basically they couldn't do viewings during the week.
I think next time we will call around on a thursday and friday and try to make viewings to see a place on the saturday. I've been really frustrated at not being able to get a viewing without giving like a week's notice and would be horrified if I found out that my agents were too busy to show my place. You can ask them about that, but it might be better to do some spy work.
Despite the general slow down, our particular neighborhood has remained popular and we should have negotiated a bit more with agents. You might not be able to do that at the first meeting but if you narrow it down to a few perhaps you can call and say, we've narrowed it down and think you can do a great service, but can you come down at all on your rate?
We negotiated with two firms and they agreed to let us use both of them and still only charge the sole-agency rate. I think it is definitely at least worth negotiating down the tie in period.
We weren't very happy with one of the agency's write up. It was very spartan and just didn't sell the place very well. We should have read his existing ones to get a better sense of this before hand.
What else... One of the firms had another property on that was just one block over that was under offer and they had a buyer who hadn't gotten that place but was very interested in the neighborhood. We didn't go with that firm but I'm 75% sure that our buyer was indeed that buyer, but registered through another agency They'll probably bs a bit, but its worth asking about what properties they've sold in your neighborhood and who they have on the books already.
They should definitely advertise in Rightmove and find a property.
I think it's also worth asking what you can do to make the house more marketable. Fresh set of eyes might have some tips you hadn't thought of.