Among my contacts at SFDC, this is a "hot" feature request. Somehow here in Germany a lot of people come up with that requirement. At sf1 world tour in London, I attended the breakout session "Salesforce1 Platform Roadmap" and it was said, they are working on that, but at the moment, there is no offline support.
So I would say: no offline support for now. I will verify this on the sf1 world tour in Munich on July 3rd.
It is possible to show all those feeds, including "To Me," "Bookmarked," and "All Company" using the ConnectAPI classes.
http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_classes_connect_api.htm
That will have everything you need to create the views. Is it a lot of code? Absolutely. So I guess you are correct that it is "from whole cloth," but at least you can reuse Visualforce Components to show feeds since you're going to use Visualforce instead of regular html.
Best Answer
At the moment, Salesforce1 is not capable of serving VF pages offline. This has been discussed here as well.
Quoting the Salesforce1 guide: - Salesforce Classic remains the best option if you need offline support, - use of Custom App (not Salesforce1 Platform) to configure and control complex offline behavior (Mobile SDK only)
FWIW, there's an open idea for Salesforce1 offline support if you'd like to vote for it.