See, this is what I think is the inherent problem with FCP's media management. In order to keep everything organized, and especially when I'm working with multiple projects at the same time, I make a new folder on my hard drive PER PROJECT where I keep all my music, sfx, gfx, etc. and make a folder called FCP PROJECT. This is where I keep the Scratch Disk, Autosave Vaulteverything from the System Settings.
It's easier organization, and it's much easier to find the things that pertain ONLY to your project than having to go into FCP Documents on your system hard drive and try to find exactly what you're looking for when you're working on eight projects at the same time.
Granted, this is how we do it because I'm a full service post house that runs Avids, FCP systems for offline and online editingso the level of organization must be greater when handling that volume.
Obviously, for a prosumer user it shouldn't have to be the same. It's just something that my Avid has that makes things much more streamlined and easier to organize for high volume. But it's a good practice to get in the habit of doing, especially when working with FCP.