this thread kind of reminds me of the prometheus thread, a lot of so called plot holes are simply people missing bits of the film or not understanding/remembering what was shown or said.
Also, with works of fiction, we have to take a lot of things on faith, not everything can be explained in minute detail. Take Bane - he has obviously had a tough life, that much we know. Was he born in that prison, or was he even born in a prison at all? We are left unsure, but he does state that he was born into darkness and didnt see the light until he was already a man. Either way, its safe to say that bane had a less than ideal upbringing and somehow found himself in the prison with talia. He was mutilated whilst trying to save talia, which is where the mask came into play, and its clear from those scenes that the prison back then was a far worse place than it is now. Now the prison is under banes control, and the prisoners are obviously kept in check by their fear of him, whereas when bane was in prison, it was obviously more "wild".