Re: How do I set my homepage to show the activity feed?
Same wish here!
In Jive I was able to create a group which contains a "Recent activity" widget, which could be configured to collect threads from all areas I am interested in and presents them in chronological order. Drawbacks were that after the last update of the Jive software we did not see who posted last in that list and that list also was not extendible to more pages (but at least it was possible to configure it to show the last few hundreds of posts).
In Lithium the feature of customized groups and widgets seems not to exist or at least is not offered to us.
Generally I consider the change to Lithium a big step backwards for various reasons.