Jens - Robert de Neufville pointed me to your excellent essay. (Rick, I'm glad to have found your own work this way as well.)
I feel, as you do, that comprehensive sampling and archival as an approach to mitigating existential risk (by placing a floor beneath civilization's potential or capabilities) is very important, perhaps moreso than is yet realized. I admire the multi-level approach you propose, radiating and scaling efforts out from concentrated, institutional instances to distributed, less formal instances.
This varied and scaled approach is the one I also support in my own work on this subject, a practical proposal called the Vessel project -- "vessel" in its various definitions as receptacle, container, conduit, medium. My own efforts are sketched at: http://labs.vessel.cc
The Long Now Foundation is mentioned above -- I have been working with them as an Intern over the last year, assisting in the initial curation of a core collection for their San Francisco headquarters called the Manual for Civilization. Though it is a small first step towards comprehensive archives centered on civilization's resilience, it's a crucial one. I think a key is to encourage as many approaches to this task as possible, and to strive for hybrid vigor in a diversity of solutions deployed around the world (and beyond its surface). http://blog.longnow.org/02014/02/06/manual-for-civilization-begins/
I'd love to correspond further, and for us to keep one-another informed and involved as our efforts progress. The more fully such proposals and efforts become aware of one-another, the more fully we can collaborate on this type of strategic approach to existential risk.
Great to become aware of your work,