Definitely talk to the theater owner/manager and get permission before you do it, if you don't beforehand you are liable to at a minimum have a problem with security. I have a friend who owns a theater, if they were to receive a complaint from a parent that unknown people especially if the group was predominantly male were handing out candy/goody bags he wouldn't mess around cops would be waiting by the exit for them. I hate to say it but at least at his theater Bronies are greeted with a bit suspicion, they really weren't being that disruptive during the first film but there was at least two or three were getting caught trying to record parts of the film on iPads/smartphones per showing, the movie had a unmercifully early start time so he actually would have to call more staff in early just to watch out for people trying to record the film.