Can Analyzer find unused design elements?

Analyzer does not do this out of the box, but you can find some useful information in the references and dependencies views.

These view will show you design elements used by (References), or needed for (Dependencies) other design elements. 

For example if a code library that is in your database is not listed in either of these views then it is probably not being used. I would test this by renaming the library and recompiling all LotusScript to ensure it does not cause any errors. If not it can be archived or deleted.