Mentions/Faves: This is, in some ways, a tough one. RSS has no way of enforcing this kind of behavior (where you get notified if someone "mentions" you somehow).
Now, sure, in some ways it's actually quite simple: microblogging clients could just implement webmentions in some form. So everytime you included a link, it would look up the site in question and discover where to send a notification. To get twitter-style mentions, we could, say, agree on a standard notation where @joeldueck.com could mean http://joeldueck.com, so the client would know where to look for the endpoint.
But the fact is, there's no way to guarantee you'll know if someone mentions you, because there's nothing forcing them to send that notification.
Likewise, you can't guarantee that by mentioning someone you'll pop up on their radar, because they may not have implemented a way to receive those mentions.