When I finish reading a particular feed, is there any way to reread it? Can I get access to all the items in a feed, not just the unread items? Or is “All” vs. “Unread” a permanent setting that can’t be toggled easily?
You can easily toggle it. It’s in the feed title bar in the story titles pane. You can configure it per-folder and per-feed. You can also hit ‘r’ to reload a site.