Ha-- good catch on the glass. I only used it because it came with the software and wanted to use stuff that was either included or free (like the background node material). I switched it out to ghostship's commercially available glass pane in the render I am using now.

Ceilings are heavily dependent on situation for me. I wanted to give a simple method that would help with getting s better result without adding too many lights or resulting in a lot of editing for someone who is starting anew. Your method is, of course, better for those who know what they're doing and are no strangers in the material room.