I think a problematic part of Revit is the interface for choosing components. Looking through that long list takes too long and you forget half the things you import. That's what I was so excited when I heard about the "Purge" command. "Purge" will remove every component loaded into your project that is not currently placed anywhere in the project. Go to File-->Purge Unused
Revit will remove all the unused bulk for you. You can go through the drop down menus and check or uncheck items if you want them to stay or go. The person that alerted me to this command mentioned I should uncheck the curtain walls in case I wanted to use them later. So, if you've been binging on components, you can purge a few away.