Lightroom uses a library to hold the edits and metadata for your images.
You can browse, tweak and yes, delete photos within your directory. It will publish to the directories as well. In fact, it won't even touch your photos. Lightroom actually uses the directory structure you define, and will use it happily. Doesn't Lightroom use a Library? Yes, Lightroom uses a Library, but perhaps not in the way you think.
