This all sounds like a login problem. You did not need to re-create anything. If you have a backup, restore it, and log in. If the site is nor recognising the password, build a temporary page to execute a forced password reset. Then the link will re-appear.
As far as the YAF search, I think this is the FTS index. You need to re-run the SQL to create it, or, as the message states give the current user dbadmin rights to the database.
HTH
:)
.....the man in black fled across the desert..........and the gunslinger followed.....