I got these ideas from playing the game and finding out that a max upgraded Barracks and Outpost have makeshift bow towers on top of them.
so first idea
Since this game somehow supports structures you(and the monsters) could walk inside, i thought wouldn't it be awesome if some of the structures had gates which would allow you(but not the monsters) to enter the structure and allow guards to shoot arrows from.
Couple that with the extra bow tower that the Barracks and Outposts receive, it would look really awesome, and allow for some level of protection when inside the village proper.
As for what structures should receive this sort of treatment, i'm thinking of like the camp when it reaches the level of keep or higher and the max level Ancillaries should receive Gates and Towers. Since the Barracks already has a tower at max level, i think it should get a Gate in the lower levels. Maybe the max level infrastructure, max level storage buildings, and the High-quality Housing should receive just gates so they look and act more fortified.
As for balancing, maybe the gates should break open for the monsters once the building dips below a certain percentage of its health.
--Self Preservation Ai--
This is actually hoping that some structures get gates. It's a simple suggestion for the Ai of the villagers when they spot a monster. Instead of running around like a madman and not doing anything to help, maybe the non-guard villagers could instead run into one of the fortified buildings and actually use their bows.
As for the guards, maybe they could fight until their health goes low, retreat into one of the fortified buildings to heal, and run back out once full.
Thats about it, hope someone at the very least reads this, im loving the game and hope it continues its development.