5. Is there value in letting the organization as a whole know how decisions are made and the rationale for killing projects and the reasons for failures?
Yes, in organizations that foster a culture of honest inquiry; no, when the principle follow-up to anything other than success is identifying the most likely scapegoats. As I've mentioned, the point goes beyond changes to procedure -- the point is improved understanding of How Things Work Around Here. Everyone benefits from knowing the answer to that question.
6. Do real organizations actually allow this kind of scrutiny and real accountability to happen?
Some yes, most no, although "accountability" is a red-flag word in this context. Organizations that make use of phrases like "We hold people accountable" are the ones that have turned blamestorming into a core competency. The scrutiny should be about what went wrong and what about the system allowed it to go wrong, not about who made a mistake and what the consequence should be.