Yes; a different one of the “ten commandments” Szilard tried to live by (they’re really short and are worth reading IMO, will take you 3 min) was “never lie without need.” (This ofc suggests there are times when one does need to; and Szilard helped many Jewish families get out of Nazi Germany at the last minute, in addition to convincing Fermi to not publish; so I would guess he navigated many actual such needs).
In terms of what’s a “need” to lie: IMO the differentiator between “worth lying” and “worth telling the truth” isn’t the stakes (AI existential risk is of course extremely high stakes); it’s more like, how much one needs to avoid “isolation” / having “the meaning of life slip through your fingers” vs how much one needs to get people to do something very specific and local that one already has a sufficient map of, e.g. to walk away from the attic containing Anne Frank. This claim is similar to the claim that AI risk is not well-served by some “emergencies”-suited heuristics, despite being hugely urgent and important.
Yes, but: a ~200 person tribe still limits the total amount of know-how that can a given tribe can remember and pass down, and then the next tribe over has to remember most of it redundantly, rather than specializing in something else.