Hi,
DISCLAIMER: Personal insight and not legal advice by any means, validate your own information.
I have a resident permit to carry concealed. The way my CCW instructor told me about a licensed establishment was that if a resturant or any type of business put a sign up when you entered the establishment that indicated that it was a weapon free zone then you as a CCW holder couldn't legally carry in that business. Hence if you carried in that business that was posted against weapons then you would be in violation of that statute. I've never came into contact with a business that has that posted in the state of Maine. Rule of thumb I follow with alcohol is that if you are going to be carrying a weapon it's a good bet that you shouldn't be drinking something that impairs your judgement. I'm not saying that you are by any means I just wanted to put that in there. Maine in my opinion is a very gun friendly state and have very minimal laws on right to carry and we've seen great success with right to carry.