It would be nice to be able to delete files and groups of files (albums, artists, genres) from Elisa. I'm not sure where this would fit into the UI well without making it too easy to click accidentally or too obtrustive. The View Details window for tracks could be a place to add a button. Also the top right of the album view in the middle pane could be a good place. Of course, this should have a confirmation dialog before deleting the files.
Have you considered Dolphin (incl. the Information sidebar), Kfind, Kid3, or a combination of these for such large-scale management? The main job of a music player is reading files. Destructive editing can be easily confused with clear-playlist actions, which adds anxiety about the software's function.
Yeah, I would tend to agree.