Wow lots of great info! Thanks guys!
@John I think the way the whole Library thing works is that W7 has its usual data-dump folders - Documents, Music, Videos etc - and each corresponding library link is just a window that displays all of the contents of the desired location in a single window. So you can include as many folders in a Library as you want, it's true, but I'm concerned with the contents of the original "Documents" folder, for example.
The reason I'm doing this is because I'm trying to minimize 1) the amount of space taken up on my small SSD RAID array, and 2) the amount of writes to the same SSD array to maximize life span of the drives.
It's been my experience that you can change the default data location of some programs, e.g. iTunes music doesn't HAVE to be in C:\users\Your User Name\Music\itunes, but you often can't change that location for other programs, e.g. my crappy webcam software and the save-game locations for most computer games.
If I created another folder, say, F:\Documents and included it in my Documents Library, any program looking to install to C:\Users\YUN\Documents would have to be manually changed or the data manually moved each time it was added. Back up would work though, but it would kind of defeat the purpose
@Hawkeye - great suggestion! thanks!