Re: Selective content on site wide activity feed
you should all check out the bleeding edge trunk 2161. It’s pretty stable and likely addresses all your SWA filtering and grouping needs, with the ability to be tweaked further.
SWA customization really boils down to the ability for a user to choose any combination of “who’s” and “what’s” which is what 1.2 does exactly. so, for ex. you can combine My Friends (who) and Forum Posts Only (what) You can create custom “who”s eg a particular group and add that button or combinations of “what’s’ if it suits your site’s m.o. Combine this with 1.2’s inline commenting and people will never leave your home page 
You can see an example on my dev site -> http://mjpratt.com
