Yes. (I say this with the experience of always going to the secret room if I have bombs to spare, and having beaten Sheol dozens of times.)

Does every floor contain a secret room?
I use drupal 6 and ubercart2. Loading of cart and checkout page takes a while so I am thinking about removing any js and css files which are not used on specific pages.
What would be the ideal way to do it? I know about js agregation but want to try the first approach.
Thank you very much.
