This is a interesting component. If it works it will be very nice. However, I had to fix two bugs in the file "admin/models/documents.php" at lines 126 and 135 to make it stop complaining about jos_groups table and access.name do not exist. The expected values should be jos_usergroups and access.title. Could not create folders or even change setting for the root path for documents.
Sorry for making this review sound like a bug report :(