Here you go, an interactive map of all the Disney areas with smoking areas marked
Smoking Areas
The last time we were there (a few years ago) my mom was using the e-cigs, and she "vaped" all around the parks. Out of the week we were there, at all 4 Disney parks plus Sea World, Busch Gardens, and Universal, only one employee said anything to her, and that was a real grumpy woman at AK. I think she was just looking for someone to yell at. Granted she wasn't using them in queues or inside the show areas where we were in forced close proximity to other people, but just walking around on the sidewalks she was. If your brother uses those, they're a little easier to deal with (no 20 minute smoke breaks every 30 minutes

)