Hi Lesley,
It's such a joy to hear how your trip is coming together! As others have said, and I'd certainly agree, Cork is a wonderful spot to add to your itinerary and there's so much to see.
The colourful houses are actually a part of Cobh, which is just a bit of a drive from Cork City. It's called Bandon Hill, or the Deck of Cards, and it's quite a sight in person (
http://bit.ly/2MeRZWU). Indeed, you can see the harbor from these houses, and can even get quite the view of St Colman's Cathedral.
As for the English Market, their hours do show them as open between 8a - 6p Monday through Saturday, though last year they were closed January 1st. What I'd recommend is contacting them directly, just to make sure that they're open when you and your husband stop by the city (
http://bit.ly/2QbVxdN).Lastly, that's not a silly question at all! Ireland has a rich and deep culture, and different counties or cities may have their own unique rhythm, sound, and song. The music in Cork has a beat all its own and this article touches a bit on how unique it can be (
http://bit.ly/2SdPQi4). There are certain pubs in Cork which feature broader music, as well as those which are quite regional. For a good taste of Cork music, though, I'd recommend Sin é, which is a wonderful little pub in Cork with a sound all its own.
I do hope that this helps!
~Rochelle