You're describing exactly what streams do, displaying the latest activity of everything you're following with snippets of the original content and the latest reply or comment on an item:
The goal of a stream is really to provide a comprehensive list of recent activity so that members can quickly review the headline, body copy snippet, and latest reply to see if they'd like to participate. I know it's not presented in list format you're looking for like the "Recent Content" view, but I'd argue that the body content and context of the latest reply is really helpful when skimming al the latest content within a stream, and you'll notice that it alerts you when you've viewed all the latest activity since your last visit to the stream page with an "End of new updates" break:
You were correct that the recent content widget for the Mathcad Overview page was not properly displaying sub-community content, but that has been adjusted:
I'm also working with Jive Support to see if we can introduce a "more" button to the recent content widget.