Greg, I don't know about the beer. (Don't touch the stuff [and YES, I am a Caper!]).

Cluin makes some good points. Eastern audiences (in particular Nova Scotians and Newfoundlanders have no problems joining in on songs.
Not sure about tips, but depending on service, I average 20% to 75% or higher.
Maritime venues are better for performers than Ontario from what I've heard. Performers get paid by the venue here. I've been told that in Ontario it is much like the states where the performers are much like buskers and pass the hat after a performance.

Willie-O is quite right about the Celtic Colours event. You'd get to see some of the best musicians of the "Celtic variety for 10 days all across the island. Incredible jams in the late evening through the early morning (11PM through 8AM). IT runs just prior to the 21st. This year, the celebrations run between October 8 and the 16th. Check it out at Celtic Colours Website. Not much specifics on this years performers yet, but that will show up in a few months.

Come on DOWN to the Maritimes.