Quote - > Quote - My suggestion is to keep it there.

Yeah, that's not gonna happen, not if I can help it... I prefer keeping my Library well-organized and fluff-free.

Yes, but the comments you've gotten so far are the simplified ones.

Even though the main folders to remain are the runtime and the data directory, those files are interfaced from the other directories using DAZ user facing files... the .dufs, which access information found in the data and runtime files. So removing just those directories, leaves files that you may need if you do do decide to load up characters and textures. This leaves orphaned files, things that may not run, and a cluttered library. My suggestion about the Dimension3D tool is if you really wanted to clean up the files this will show files that are part of a particular product, because you just haphazardly delete directories, you will not have an organized file system as you want.  So you may think just simply deleting directories will clean up content, you're actually doing the opposite.