You've probably gone by now TM but for anyone else here are some local dishes that my MIL (who's Polish) cooks.
Placki (Potato cakes) - grated potato made into a flat pattie type shape and cooked in oil (I like these!! You can sometimes get them from the street vendors)
Golabki - Cabbage leaves stuffed with minced meat and rice - MIL serves this with a delicious tomato and onion sauce.
My husband and I went to Krakow in December the weather was cold but crisp.
If you're into shopping there's a big modern shopping centre (similar to those we have here) that's full of designer shops and cafe's. It's not in the main square area so you may have to ask directions, or ask in your hotel (they may have a pamphlet)
We found the restaurants in Krakow very much international - we were a little dissappointed as we didn't really get the chance to eat 'proper' Polish food. The one time we did find a restaurant that did things my husband recognised it shut at 19.00 and we missed it.
Krakow airport is tiny!! The duty free shop is miniscule and I wouldn't like to be there at peak times
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If you want to bring back drink etc I'd suggest you buy it in the city and pack it in your suitcase as you can hardly move in the shop. As soon as your through security that's it - your in your departure lounge. There's a bar but everywhere is no smoking so if you want to wander a round or smoke I'd go through to departures as late as possible.
If you need anymore help just let me know.