Re: wind conditions and reefing
I would use the gust figure to make my sail area decision.
Suppose the forecast is understated? Better safe than sorry, especially for just recreational sailing where you're not trying to wring every ounce of speed out of the boat (and you have other racers around in case you find trouble).
30 knots is enough to make you heel a lot, even if you luff everything, the sailcloth still has a lot of wind resistance. Some boats more than others, but if you're new, 30 is not something you want to mess with yet.