Local rules as well as from LFL, may dictate the use or lack of use of a blaster at events.
Recently form LFL a request was put out not to use weapons at official events in these areas "We do find ourselves in an era, however, in which the appearance of realistic weapons in public is becoming more and more of an issue. Because of this, a general request is being made for all official appearances in the European, Middle Eastern, and African regions, that replica blasters (or anything resembling a real-life firearm) not be displayed in public. Please note that this is simply a stated preference, and one that only applies to cast and paid appearances and open invites initiated by Disney and/or Lucasfilm."