How would I convert an RSS feed into an ebook? I know that calibre can already do this but it is a bit bulky and I don't feel confident writing a recipe in Python to try to do this. I do have access to pandoc and other tools on Linux, though.
http://newstoebook.com/¹ I've been using it to create ebooks of one of my project blogs. The resulting ebook (I create .mobi books for Kindles) have been readable. As my blog increased I found it only extracted the most recent posts, so you might want to monitor for this behaviour in case it affects the feeds you want to read as an ebook.
¹ No longer online (archive).
If all you're wanting is to easily get specific RSS items to a Kindle, Instapaper has a service that makes this very simple:
That's how I do it, and only for specific posts that I'm actually wanting to read on my Kindle. My usual workflow is when I'm reading through my feeds on my iPhone, I click "send to Instapaper" on longer posts that I want to read on my Kindle.
There is a node.js project for this https://github.com/gonejack/rss-epub