We have friends who bought in 4S last year, (not Pienza) and actually seemed to get a better deal than builders are offering now. Not really sure what’s going on with pricing at the moment, but I still wouldn’t hesitate to make an offer to the builder if you are serious. Get the name of the VP of Sales, or higher up, (that’s what our friends did) and present the offer directly to them, and see if you can make the deal you want.
As far as the fire concerns go, we own a home in Rancho Santa Fe, and we have fire concerns, too. Even some friends in Del Mar, Santaluz and the Crosby were evacuated during the past fires. If you can stand the traffic/long drive times and airport noise, you’d probably be better off buying in Carlsbad or Oceanside, if this concerns you. Personally, I’d never live north of Via de la Valle, or south of 56.