Regarding one of your queries, you can use Brucey's fantastic cross-platform module called BaH.Volumes that will get you the location of Documents, Program Files, App Data and also tell you how much space drives have left, and how big they are, all through simple commands.
You can download it here or via syncmods using the following command line:
syncmods -u forumusername -p forumpass bah.volumes
You can download it here or via syncmods using the following command line:
syncmods -u forumusername -p forumpass bah.volumes