The "boot" drive, which I am assuming is my "project drive" has 465 GB capacity, with 184 GB available. Its format is "Mac OS extended." I am assuming this is the computer's hard drive? The volume where it is telling me I am out of space (called, "+") has 465 GB capacity, with 670 MB available. Its format is "Mac OS Extended (journaled)". Thus the contradiction: if both of these have 465 GB capacity, why does one have only 465 MB available, while the other has 184 GB available? And why does the Volume "+" drive show nothing inside it indicates there is anyting on it related to my project?
If I follow this "scratch disk" thing correctly, a scratch disk is a seperate folder created from your hard drive on which you store and edit your FCP project and its associated files and meta info. Which begs the question: if the scratch disk is created form the hard drive, and linked to it, why do you need one at all? Why can't everything be done on the hard drive alone? You don't need a scratch disk to store and work with jpeg photos, MP3s, documents, etc. on a PC.