From my experience with beardies, gender doesn't really make a difference with how docile they are. Age does though, young or baby dragons can be hyper. I was surprised the energy level difference, even just from the 2 year old i knew, to what my 7 month old is.
Before my baby girl, i've dealt with three adult bearded dragons. A female about 7 years old, a male of undetermined age, and a 2 year old female. For the most part when you picked them up, they all just sort of layed in your hand. Though, we all have our days wjere we don't wanna sit still. The 2 year old and the male, liked holding onto your shirt. While the 2 year old also liked running up you or your arm to hide in your hair.
From my experience, as much as i love my baby girl. If you are looking for docility (not sure if that is a word.) Try to see if you can find an older dragon, one at least full grown (2 years of age.) They should calmer and easier to handle for longer periods of time. At least that has been my experience with dragons.
I'd think they do fine in a classroom setting, just make sure you get your set up and tank size right. Also, before you let your dragon meat the kids. I'd get to know him prettynwell first, like most animals. Every dragon has its quirks and better you learn them somewhere controlled.
Oh and as far as good around kids? Remember those three dragons i meantioned earlier? Well, that was from when i volunteered at a nature center. They were constantly being taken out for guests and shown to and petted by kidsnof all ages. The 7 year old female was part of our party line up and she'd just lay on your head. None of them ever seemed to have a problem being around kids.