The Crawford should be worth a look, that bulbous extension they put on a few years ago doesn't seem to photograph very well . . . . it'd be good to hear a decent first hand appraisal of it, Starch.
And since you're going there anyway, we could use a good, high res, pic of the mid 18th century 'Panorama of Cork' by Butts, which is in their permanent collection, should be prominantly displayed.
I've marked the bit we need: which is from the entrance to Patrick Street right over to the frame on the left.
The Crawford don't allow photography so you'll have to be cute about it, maybe get wife/girlfriend to set up a minor diversion [I'm thinking low-cut top, but lost contact lens could also work].
If you exhause the contemporary/exciting delights of Cork City sooner than the three days set aside, there's a house on Cork Street in Kinsale that needs photographing. You'll know it when you see it - complex curvilinear gable - only one left in the town apart from the Market House, I think it's currently painted yellow.
A street view would be fine, I'm not sure if there's a good vantage point to the rear. Just occured to me that a good shot of the roof structure is probably achievable from the 'French Prison' museum, which is near by. Obviously if you have other things to do, that's fine as well. If, by any chance, the front door happens to be open, get a couple of shots of the stairs.
Again, only if you run out of things to do.
It's not absolutely crucial.
Nobody's going to be disappointed if you can't get everything.