Perry - it was an OKM in about '72 as HS said. I'd guess that a BOE of the sort you mention would very likley be on the authority of that OKM. It is unlikley (but might happen) that a BOE would have 'new light', more likley a new shade on an old lamp.
As to 1), there is more specific detail on certian DF offences in the Flock book (and maybe letters etc) than in the public materials. The common one that gets quoted often is the more explicit description of pornia in Flock compared to the WT. 'Borderline cases' might be technically grey areas according to the WT, but are DF offences according to Flock. If a new elder reads Flock for the first time and has a guilt trip as a result of a 'grey area' indiscretion years ago (and has been a good boy since) that he now knows to be a DF offence and confesses, he need not be removed and reproved/DF as a result of this.
I'd suggest it's sensible and preserves some Christian charity and fairness. I'd just like the same charity extended to all JW, not just those who get an appointment. I seem to recall the discussion months ago. I think that's all it was, no big deal.
Max