To clarify: yes, snap restore can restore single files or volumes (or aggregates) -- but no, it definitely cannot restore directories or qtrees.
In order to restore a directory, you would need to do a drag/drop or cp (via .snapshot) from CIFS/NFS, or use ndmpcopy from the command line.
LUNs should be snapshotted and reverted using SnapDrive.
Hope this helps.
Cheers.
-A-