@Madfox, I like the scope of what you are building but the scale of the windows are wrong. Try using wizwin1_8+window1_2 to create long thin windows or download my
latest map and take the window texture from there, they can be setup to be any vertical size.
I think most of the external trim detail on the outside of the building can easily be converted to nice angled textures and will still give the same impression as all that brushwork. The lighting is so bright you cannot pick out the brushwork detail and it could be converted to textures with painted shadows without any lose of detail.
Your spiral columns need to be more solid and look like
columns that could support a ceiling. The spiral design is suppose to be decoration around a solid piece of stone.