I think i've asked about it before but now im gonna do it again.
It would be great to be able to select an self made template file to render the rss xml file, just like sitemap etc.
It's very frustrating that you have no option to change the output of the RSS module.
I've made it possible with somewhat of an weird hack with taking the html template turning it into the xml file and replaceing everything around the html template formed as xml with nothing.
But would be nice to avoid all that and just get an option to select an template file where u can transform the rss feed as you want :)