Given the amount of qt apps and lack of gtk devs, i don't think sticking to stock rss is a necessity here.

would it not be simpler to extend what you've got to cover text/web feeds? The sample xml file on the website already contains a media tag, so why not just add an extra type here and a simple renderer using a textbox or qtwebkit if necessary. Then it should (but probably won't ) be as easy as detecting feed type on click and selecting appropriate renderer.

In all honesty, I've always thought of the stock rss app as less integrated than the rest. It just doesn't have the same appearance or polish. Might be the split window vs stacked that does it.