I agree, we should leave it up to the user how she wants to retrieve the notes and for me a 1-5 star rating and the filter along stats (which note did I generate most recently independent of in which notebook; which note did I edit, read etc the most often - or never?) would be helpful add-ons.
The tag workaround of $,$$,$$$ etc goes some way but Evernote might want to provide more elegant approaches... any other ideas?