Avoid the Plough. It used to really rock there and the beer was very cheap but Sam Smith stopped the music, a sad sight to walk past a silent pub during Folk Week.
As a group you will need to walk around and find a space early in the day, the pubs fill up quickly and stay full before lunchtime. Loads of fast Irish played everywhere. Good luck finding accommodation and a venue or two.

G/F may like to meet fellow unaccompanied in the side room of The Station Inn. Good evening session in The Endeavour every evening run by Maggie and Les very mixed bag there and your sort of stuff would be welcome, don't know about a whole band though.