This looks great, Here are a few tips I hope may help you with Lighting Design.
Calculating Lightmaps: (How to save hours of Calculation time)
When you decide to create a light that casts shadows on your map do this early on, do not wait until you have all of your objects placed. Place a few objects and create the light you wish to cast shadows and then calculate, do this until you have the correct shadows you think will go well with your map, then turn the shadows off on that light and re-calculate. Leave this light alone until you complete your map. Add any other lights without shadows and calculate as you go. (None of your lights have shadows so calculating is very fast) once all of your objects are placed and your map is done go back to the light you wish to cast shadows and check the box to again cast shadows. then re-calculate. This will save you hours of Calculation time if you use this method.
Add Custom Lights: (Very Helpful)
Doing this will save you a great deal of time and unlike creating custom lights on the fly the map will not need to be saved and re-opened before you can un-check the Cast Shadows box for each newly placed custom light (Again can save you hours of labor) This is also useful because you can always have your favorite lights available without the need to configure them each time. To add custom lights to your brow edit use this method; Go to BrowEdit Directory, Data, Lights.txt Open this up and you should see something like this:
<light> <name>Torch Gigantic</name> <color r="1" g="0.5" b="0" /> <range>100</range> <brightness>230</brightness> <maxlight>256</maxlight> <givesshadow>0</givesshadow> <lightfalloff>1</lightfalloff> <height>55</height> </light>
Edit these entries to your specifications and you will have all your lights available with just a few clicks. Save reload and tada~
I hope this helps you in some way and keep up the great work.