Not sure where to place suggestions so I will start a thread that anyone can add to. I think on submitted articles it would be nice to have the submission date shown without having to open the comments. Maybe also have a date for the latest comment or something to that nature.
This is something that has been suggested a number of times, so many, that I might enable it as a toggle option. However, we try to focus less on timeliness and more upon the quality and thoughtfulness of the content. That's primarily why we chose to leave that information off of the feed page. BTW, I follow #suggestions, so I will see them. If you find a bug, report it with the tag #bugski.
I've seen it happen multiple times where old posts have become active from a person commenting on it. If you do this, I would definitely prefer it as a toggle option with the default set to "off".