From my perspective the four problems areas that were partly elaborated on the blog and also fed into the discussion topics below are all interrelated. I don't believe you can arrive at independent solutions and expect them to work as a whole (not suggesting that is what you are actually trying to do but has an impact on the discussion). Normally in solution design there needs to be clarification of the "business" requirements, objectives, related activities, end-user requirements etc to clarify the role of the project and the interrelationships between the parts before you can get into the detail, flexibility requirements and technical requirements. I am worried to see an early suggestion of any technology, standard or specification in advance of clarifying the sorts of requirements that should drive the design and then the development. Perhaps that is just my solution architecture bent, but I often see problems arise when the technology drives the agenda instead of serving the agenda.
The clarification of the end-user requirements and project scope and responsibilities, etc will tell you a lot about scale, community of practice engagement, "plugins" to the NLR, augmentation practices of target communities (and therefore crosswalking/harmonization requirements) etc.
You are all smart people, there is no doubt about that or the kinds of issues raised here would not have been raised already, so I am sure that you will be thinking a lot about the issues I've mentioned. It would certainly help if we had some further insight because it will help us to provide more focused information into your activities.