NewsBlur is great, but if I understand correctly they mark items "read" if they are unread for 14 days.
It's got a bunch of other features that are superfluous to me, but that one bugs me a lot.
I'm using Feedbin (
http://feedbin.me) which definitely satisfies all your criterion. Also it's fast and seems low in bugs, which is more than I can say for most of the alternatives.
I guess I can't speak for the Feedbin Android clients, but there are a couple. You can definitely easily "share to facebook" quickly from the web app.
It is _definitely_ not a solution for the diaspora - your starred items can become an RSS feed, but unlike Google Reader shared items, those entries are not treated specially inside Feedbin, so you can't pivot back to the original feed with a single click. Yes, I'm still bitter.
I'm hopeful that Digg Reader will become the holy land - it seems like their "Digg" feature, as they've applied it to their Reader, could do exactly that in the future. However, right now, there's no way to unmark an entry as read, and there's no way to view only your unread items. Those are their top two next planned features, but it's June 1st already. Got to have an answer for now.