Even further ideas that I like! Yes, Your Content should exactly do what it says: giving you an instant overview of ALL your content. Indeed like you are saying: threads you started, posts you made, likes you gave (we can only now see the likes we received) and comments we made on profiles (and in the future blogs and CMS articles, but let's just take it step by step ). It will do wonders for the use of/(inter)activity on content. Awesome.
but maybe in addition to this, just display all content by default and have a drop-down or something of that nature with options for what categories you would like to display content from like a mini-map of the site hierarchy for easy selection.