What I want in a feedreader

I have been using Google Reader for a few months now and I have come to realize things that I would love to have in a feedreader.

For one thing, I would like to be able to “tag” feeds and specific articles in a feed for organization and easy lookup purposes. It is cumbersome to have to go and manually find an article down the road from when you read it originally, tagging would make the process a little better. Google currently has the “Star” feature, which is great, but it leaves articles all in the same category, “Starred”.

The folder/category concept in Google Reader is great but lacking. I would love sub-categories and the ability to temporarily disable a feed being updated.

The penultimate feature would have to be notes for articles. Adding a note to an article that I read, then sharing that article (and the note) would make life a lot easier. This leads into a small feature that would also make reading and sharing of articles much simpler, sing article sharing. Sometimes I come across a single article who’s parent “publication” has a feed. I do not necessarily want to subscribe to the entire feed, but instead the single article.

All of these features would make me an instant fan, in fact, I might even be willing to pay a small price to use those features. Suggestions?