Mail - Deleting/Hiding Exchange mailbox's (e.g. RSS Feeds)
There is a way to removed the RSS Feeds folder from Outlook 2013 using MFCMAPI
http://mfcmapi.codeplex.com/
there's a youtube demo here as well
https://www.youtube.com/watch?v=-g45GbCOjx0
Only difference with Outlook 2013 compared to Outlook 2010 in video was that the RSS folder was found in the the IPM_Subtree subfolder.