The Irish MBassy is a good bad just of the main square. Would be a decent spot for watching the rugby if its on when you're there. There are good clubs and places, many in undergrund cave like structures. There are also plenty of spots to watch jazz if you're into that thinkl. We were at a really good brewery, again underground, the first time I was there but I can't remember the name.
There is also a really good chocoloatiers on the main square (near the tower where the wee man comes out on the trombone) that does hot chocolate with various flavours and all sorts of fancy desserts. IT will be a hit with the woman if you are breaking her.
Re. things to do. Auschwitz and the Salt Mines are the main things. Auschwitz is harrowing but something every1 should go to. IT was only 60 years ago it all happened after all. Salt mines are easy to get to on the tram and relatively sheap. Worth doing. Think you walk down about a million steps to get down and then get squahed in a tiny elevator coming up. But sure its a bit of craic. Wawel castle is in the town and worth a walk around, though as castles go its probably not the best.
Overall, Krakow is a great ciity and you'll have a good time.