You’ve reminded me that I’d like to eventually figure out a good way to have Yarns import and export OPML files. Given that the impetus of Yarns vs a hosted server is to own your feeds, it’s a shame I haven’t implemented better data portability yet.
Another idea your post brings to mind, is that it would nice to have an option to automatically create following posts (and add to the blogroll) when adding a new feed (and subsequently remove following posts when unfollowing). This should be fairly easy to implement, and would take advantage of Parse-This since its integrated into Yarns already.
Additional would be a bookmarklet for adding feeds.
As usual, you’re a fount of good ideas. I won’t have time to implement any of these things before IWS, but one of them might be a nice project for that weekend.