Since my spring cold is keeping me out of the boatyard, I'll carry on with this discussion.
As a race officer, trained by many talented ROs, I will run the race (under common sense) until the Chief Judge or USCG shuts it down. We have a club on our bay that is famous for cancelling a race on the day before, only to have great weather on race day. They also have displayed the propensity to grab high entry fees and remain at the bar if the weather is 'uncomfortable' for them. Their credibility and attendance is suffering.
There will probably never be an ISAF check off list for ROs to apply in threatening or angry weather, so do not look for a guide; use common sense and trust the talent of your Race Comm and your racing sailors. Be prepared with adequate safety boats with jumpers when hosting cats or the modern sporties w/out auxiliary power.
If there is an ISAF 'safety guide for race management' I have never seen it, but I love enlightenment.