Interesting suggestions! We will look into these.
4. Add a circle more walls
Two circles as I now seem few, for a large city
an inner wall more,near City Hall.
Most player strongholds are already designed with this in mind.
Orc strongholds are a bit different, but human and elven strongholds have two circle-ish layers of wall.
5. City Hall transformed into a castle
Cool idea, but it doesn't really fit with the storyline. Players won't be starting off as kings or mighty lords but as thanes ("A man who held land granted by the king or by a military nobleman, ranking between an ordinary freeman and a hereditary noble"). Much of the land was destroyed in a recent war, and now the king has employed new thanes to seek out petty estates to transform them to their former power.