well, maybe someone have already thinked about it ... but
what about an option for not-caching the no-lyrincs-found-in-lyrics-database pages ?!? manually deleting or re-searching the bad lyrics pages is boring

and what about some kind of getting artist/title info starting from the filename of the songs? like winamp do in the medialibrary ... or, even better, like id3TagIT do ... for those mp3 who haven't an id3 tagname
let me know

first, it's hard to find if what was downloaded were lyrics. if we downloaded them from database, we know it's lyrics. but if we downloaded them from unknown page, they may be lyrics or some unrelated page. it's just hard to find out.
anyway, if we didn't store this "something" downloaded, next time you'd play the song this something would have to be downloaded again just to find out it's again not the lyrics. In latest build there is a option "try to redownload wrong lyrics after a week" ... it works like this. if you play a song and text from "unknown" site is stored in your cache and it is more than week old, it tries to download lyrics again (maybe in meantime they got available somewhere). This have to be reworked little because this way also hand edited lyrics (or simply pasted into evillyrics) are rewritten.
you can use ELLO to simply differentiate between good and wrong lyrics. but we can also store lyrics from unknown sites in some separate directory .. i have to think about that
as to tagging. evillyrics doesn't read tags but simply text from winamp title. and winamp does what you're writing about ... if id3 are available it shows them, if not filename is shown. So EvilLyrics actually does what you write about ... if we understand each other