/1 You can escape by the boat without battling the magisters by the boat and kid by supplying a code that you learn by saving another magister from a houndmaster.
/2 You can exit the sewer avoiding battle completely by giving the maniac a piece of meat you get from the scene at the entry to the prison.
/3 You can escape very early by entering the underground part of fort and sneaking to the broken part of the fort at the back above the trial room and moving the boxes without ever engaging a single fight.
Fully completing every event i managed to hit level 6 as i left the fort using a combination of skills. A lot of the extra experience points came from doing things in a very specific order rather than trying to escape as soon as possible.
I was roughly level 4.25 by the time before i even started hunting down magisters etc.