I love this, especially the new update. I would gladly pay more for this program. At $10, it's practically free. Suggestions:
Flatter terrains for building towns and castles. Maybe just a flatten along the z axis option to crush the existing terrains.
Snapping to make building easier.
People. I know you've thought about it...
Maybe R to rotate buildings along the Z axis? The rotate widget is clumsy. I don't even use widgets in Blender. Just the hotkeys: R then Z for rotate along z axis, for example.
Lights. Candles, torches etc. They shouldn't be hard on the frame rate.
An FPS style walk through mode.
You've got a few stretched textures on your buildings, but I'm sure you'll clean those up at some point.
Thanks! Outstanding work. Do you have a Patreon page? I'll kick in.