I could definitely smell vaped herb before I got my own vape, but it just smells like someone opened up a big bag of cannabis, as mentioned. It definitely smells like cannabis but lacks the burning smell, so more than likely someone might think you have a zip in your pocket or something.
I stay away from people and draw from it like an ecig, but the only time I really vape in public is when having a barbecue with friends or on a walk. I do like edibles though, and often just eat some of them and if I want I will have a few pulls from the vape. It's easier that way, and far less paranoia if I don't vape at all. In my area people smoke cannabis all the time in public, but I grew accustomed to hiding my usage over the years and the paranoia won't go away.
A couple days ago some guy was smoking a joint right in the grocery store and nobody batted an eye, other than a couple people snickering. It smelled like ashtray mixed with great cannabis, such a shame!
I don't know about vaping in a movie theater, some people may not appreciate that and I like to treat others how I would like to be treated. I would love to of course, LOL. But sometimes vapor can sneak up on me and I often doze off watching moves even after only having a few pulls, if the movie is real melodic and relaxing.