I am huge proponent in favor of the 5 knot min to start a race.

If the conditions deteriorate after the start, I also feel it is the race committees responsability to try and complete any race that was fairly started. If this involves the complete shut down of the wind they may not be able to do this, but if it is dying or drasticaly vering, they can change or shorten course and still salvage the effort that has already been put out by the competitors.

My take anyway

Matt