I just got done a custom SQL alert that was a bear. the scary kind.
You need to delete your select statement so it joins in with the SQL alarm select- meaning you need a rewrite to join your containers table to the interfaces table they select from. Your entry should just be joins and then the where statement.
And I would do the joins as left inner joins assuming you only need data that does match where the interface is down vs rows that don't match the interfaces.
edit- my sql developer corrected me that your left outers are faster then what I meant to type as just inner joins.