Yes. SpaceObServer indicates duplicate files depending on configurable criteria (including MD5 checksums). These files are shown in the "Duplicate Files" tab, which also enables you to remove no longer required copies of this files. The detection criteria can be configured in the Options.
No. Empty directories do not occupy disk space on NTFS volumes, so searching for empty directories costs time, but does not free up disk space. Furthermore, there are directories in which programs place (temporary) files only while they run. Deleting these directories can cause error messages or malfunctions when starting those programs the next time.
No. SpaceObServer is not able to restrict the level of file system information that is stored in the database. The scan has to traverse the complete file system tree to sum up the directory sizes. We have to store information of all files to implement many important features in SpaceObServer like the oldest, biggest, temporary and duplicate file search and also statistics about file owner and file extensions.
Yes, this is possible. Just configure the same database connection for each instance of SpaceObServer in the options. All scans will be listed in each SpaceObServer user interface and you can generate reports and configure scans from each instance. However by default there will only be one 'SpaceObServer Service' executing scans for a certain root directory. This is the machine where you first add this directory to scan. You can configure the scanning machine(s) from within the 'Configure Scans' dialog (See: 'Observing Server').
Please ensure that the SpaceObServer Enterprise Edition is installed on the server where you execute the script. If this is the case, most likely the SpaceObServer OLE Interface is not registered properly. Please open a console ('cmd.exe') with Administrator permissions on the machine you installed SpaceObServer on. Navigate to the installation directory of SpaceObServer (e.g. 'C:\Program Files\JAM Software\SpaceObServer') and execute the SpaceObServer.exe with command line option '/regserver': SpaceObServer.exe /regserver
Please note: The SpaceObServer.exe has to be started in elevated/administrator mode in order to be able to register the COM interface correctly.