Stone walls are very expensive to build for just a bit more HP.
To add the atractivity for stone walls it would be cool if soldiers (guardians) could be added (e.g 1 for 10 blocks) - they would act as archers. Or at least in the corner of the wall.
In general:
- A nice castle main building would be great with some needs (wine, beer) workers.
Jobs like: tax collector, who will collect taxes from mid/high class houses where cou can specify what the tax rate is (low, high) and this will have an effect of the happines, atractivity, or even on produce rate, would add an additional management where you will become gold but have to be carefully…