what are your thresholds for deciding when to transition from (primarily) community-building to (primarily) doing research ?

We're not precisely sure. It's also a matter of funding. Researchers who can publish "platform research" for academic outreach, problem space clarification, and community building are less expensive than researchers who can solve decision theory, safe AI architectures, etc.

Would it not be more efficient to post the articles and books in question on Less Wrong, or upload them to Pirate Bay, or something to that extent -- at least, while you wait for the meat-space publishers to get their act together ?

Like many academics, we generally do publish early drafts of forthcoming articles long before the final version is written and published. Examples: 1, 2, 3, 4.