Re venues,

While "upstairs" or in the back room of a pub is great although not always suitable for more high profile guests, there are other possibilities as has been mentioned.

I went to a folk club held in a cafe(Ardersier Folk Club) a few months back which was very homely. Nice decor and furniture and not a "greasy spoon" type of place. The cafe was actually closed in the evening and the folkies just took it over. We could bring in our own beer, wine etc and it was a great atmosphere.

Re village halls, some also have smaller rooms attached. For instance, we always have a great time at Newcastleton Village Hall during the festival in the Supper Room. However, smaller halls themselves can also be reorganised according to the event with tables instead of rows of seats etc.
There are any number of possibilities. Bringing in your own drink is often a better experience that consuming what many pubs have on offer although there are still some good establishments around selling good beer etc.