1. If your using on the fly watermarks then this alteration should work add the code in bold to watermark.php
Code:
Content visible to verified customers only.
2. If your using on the fly watermarks may this this addition to that same file
Code:
Content visible to verified customers only.
3. User Galleries do you mean personal albums? Sure what your speaking of is two entirely different things. Moving/Deleting photos is an admin permission switch under admin options in admin panel. Whether or not a user can create personal albums is a usergroup permission under edit usergroups.