1. Yes, all the prisoners escaped among the hostages except the headmaster. One of the shots also has a hint: when the hostages get on the police car, there is a shot of four prisoners sitting in the car in turn.

As for leaving clues, there is a line that says "do things with conscience". The old prisoner who rolled down the window in the Touareg initially pretended to be a customer of the bank and was a Jewish priest. If he is really a Jew, it is easy to explain: these prisoners took the diamonds and made a fortune; He also left clues to expose bankers' war crimes and avenge Jews.