it is just for the visitors to return back to your site nothing else, but I use rss as xml sitemap sometimes
Can anyone site some proof as too their stance, since no-where on Google's webmaster guide does it say RSS won't be flagged as duplicate content
I suggest you only include the summary of articles, posts etc, in the RSS feeds. In this way, you will not have to worry about duplicate content and people will come to read more on your site.