Index cleanup/usage help
Index Hoarder is telling you that historically this index is not being used. Therefore, the maintenance of the index is a cost in CPU, I/O, and storage, but you are not getting any performance benefit from those indexes.

A general policy of considering Foreign Keys for indexes is good general plan, but an index that is not used should most likely be dropped. 

Here is a link on examining the indexes yourself:
http://www.mssqltips.com/sqlservertutorial/256/discovering-unused-indexes/

A snippet of code from that post shows some query details:

SELECT OBJECT_NAME(S.[OBJECT_ID]) AS [OBJECT NAME], 
       I.[NAME] AS [INDEX NAME], 
       USER_SEEKS, 
       USER_SCANS, 
       USER_LOOKUPS, 
       USER_UPDATES 
FROM   SYS.DM_DB_INDEX_USAGE_STATS AS S 
       INNER JOIN SYS.INDEXES AS I ON I.[OBJECT_ID] = S.[OBJECT_ID] AND I.INDEX_ID = S.INDEX_ID 
WHERE  OBJECTPROPERTY(S.[OBJECT_ID],'IsUserTable') = 1
       AND S.database_id = DB_ID()


Consider dropping the unused indexes. If you have a yearly job that would really use the index, consider creating it just for that job.

Feature-Phobic Indexes is suggesting that a filtered index may be more valuable to you than a standard index.  A filtered index would only cover the rows that meet your search criteria.   

This is a little more speculative, but the advice is to try some filtered indexes.  If they do  not work for you, you can drop them again.