Hi -
I’m afraid there’s nothing in there that will make your monster file run smoothly.
Did that file originate in Sketch-Up by any chance?
You probably need to look into joining meshes that use the same material into one single mesh to reduce the overall number of mesh objects. Extract the render meshes of (poly-) surfaces and do the same. Delete the surfaces. Reduce the amount of blocks and create single meshes.
I’m afraid there’s no simple solution to get that file to work for you.
-wim