I don't know why there should be any active ambient values for the props, BDDesign.  That was an accepted method for earlier versions of Poser, but clearly not very effective with the current.  If anything, diffuse_values on most props should not be set to 1 in order for IDL to work correctly.  The lamp lighting does appear too hot for the scene, perhaps the combination of glass emitting and point light is overwhelming.  I would try rendering with glass emitting separately from point light and determine which is better.  However, judging from the wall texturing, you may not get the desired result you are seeking.