Thanks for the comments and the rep.
The walls are very square by design on this map. When i was first messing around I played with curved walls. But when I decided to sit down and actually make a full map, I chose to reproduce (with some artistic license) the map of Loudwater from the FR Campaign Guide, which had the same square walls. So yes, you can make the walls much more organic and flowing than this.
I haven't messed with changing the angle of the sun. I know it's an option. Just not one I've explored.