These are just ideas I had, but here goes.
To maintain an 100% accurate database with track listings, year, etc. there should be an online database where users submit scans or pictures of the back of their CD's. This would be linked to the entry in the database so any user can verify the tracks spelling, order, etc. is correct. You could merge it with Jaikoz and call it something like ArtBase.
MusicBrainz is good but suffers from a few flaws, the first is track listings cannot be verified, one must trust the database online. If however users could simply look at a picture of the track listings showing the year etc. they would know completely it is right.
Another idea I've had is something foobar2000 suffers from, namely you can accidentally edit something without knowing it. If you're moving to fast and edit or change a name, delete something, etc. To solve this Jaikoz Player could be designed that lets the user LOCK the library, preventing any changes from occurring accidentally. Or perhaps you could design a plugin for foobar2000 that would LOCK the library, preventing changes and maybe even track changes made to files in a log.
The other idea I had is designing into a player CRC/MD5 checking. What I mean is the player would mark any imported files with either tags or in the filename itself with whatever the CRC/MD5 was at time of import. Then as changes are made later it would retag the file using this info. In the end you could run a SCAN of all files which would let you know if anything had become corrupt. Superior method than any others I've seen out there.
Anyways just random ideas, thanks!