hi, i'm trouble setting my rss too.
when the feed button is clicked it opens a page that says "This XML file does not appear to have any style information associated with it. The document tree is shown below."
i did set up a blog menu and have one page (the content for the that is seen in the doc tree).
in the theme builder it said in rss feed url that if you leave it blank it uses the wp default.
i also tried to add http://cinemagicalmedia.com/feed/ taking cue from your advice in this post, still linked to page with no style assoc.
right now the rss feed url is blank.
thanks for your help. i'm replying to this post bc my question is related and i've posted a few questions on the post and no one is answering any of my questions, though i see others are being answered.not sure how to get anyone to reply.