In response to item #1, we need a test, everything that a fluff know-it-all should know, so at least we have a common grounding of knowledge, and we can all answer the basic questions that regularly crop up.
For rules, as know-it-alls, we need a commitment to keep up to date with knowledge specific areas; if, as was suggested, we have Fluffmasters for specific topics, they need to be able to keep up to date with their specific area. Anyone wanting a specific position should have at least the latest addition of the codex concerning their race, if we are to split it by race, along with a working knowledge of current events involving said races (EoT, Armageddon3 etc), as these can be considered to be the most "canon" fluff for those races involved as well as for those campaigns.
Beyond that, I'm not sure. We need to have humility as a basic point though; despite our titles, we should be accepting of other people's knowledge (and also lack thereof).
For rules, as know-it-alls, we need a commitment to keep up to date with knowledge specific areas; if, as was suggested, we have Fluffmasters for specific topics, they need to be able to keep up to date with their specific area. Anyone wanting a specific position should have at least the latest addition of the codex concerning their race, if we are to split it by race, along with a working knowledge of current events involving said races (EoT, Armageddon3 etc), as these can be considered to be the most "canon" fluff for those races involved as well as for those campaigns.
Beyond that, I'm not sure. We need to have humility as a basic point though; despite our titles, we should be accepting of other people's knowledge (and also lack thereof).