+1
As for finding the hideout. I think it would be good for the quest giver to give you a the general area ("the last banding raid came from the south!"), so you go look south of the village.
Then again, if the bandits are smart, they might go around deliberately, so you look in the wrong direction?
Also, the way bandits in general should work is that bandit camps are spawned with a few parties, and those parties periodically leave and return after some time (successful raid or if they were defeated but escaped, or just after a set amount of time). With more successful raids and prisoners, the camp would grow, which means more bandits, but also more and better loot. And prisoners.
Once a camp is destroyed, the area should be safe for a while. Bandits should prefer areas of lower stability and bigger turmoil, with more camps tending to spawn there.
HOWEVER, where there are a lot of bandits, mercenaries, slavers and bandit hunters are also bound to follow. So you would have those groups roaming on the map, preying on each other.
NPC could also detect and attack camps?