A. I once made the observation, after traveling all over the country, that people will live in just about anything. I saw trailers in Tornado Alley, oceanfront homes on barrier islands just waiting for a big storm, cliff homes in earthquake zones, wood cabins in forest-fire country, and even homes that looked up at man-made dikes holding back wild rivers. Site-specific design is not underrated, but I'm sure you've seen the same bad decisions being made.
Pre-engineered homes rarely take custom issues into account. One-size-fits-all designs aren't a good idea, and not even economical, in the long run. Building your dream home should be a dream come true, but there are many issues and specific products you need to consider. Most people want something that is custom-made for their needs. Even people moving into an older home often plan changes to make the home "special." From your address, I can tell you that you require a wind-resistive home, proscribed by building codes. You need to meet seismic requirements, energy codes, and a host of issues meant to protect you and your investment.
What I've found in the few experiences I've had with pre-fab homes is that the companies that build them aren't necessarily oriented to your local and state codes, nor are they flexible when it comes to tweaking their stock designs to your needs. I can't say that all companies are like this, but I think you should get what you want, not what they steer you to, and I doubt, when all is finished, that you will have saved a dime.
I'm in the middle of a project that's pre-engineered, and it has been a series of problems. The Canadian company had plans redrawn for production that were altered from the owner's original requests and had to be changed back. Windows that met energy codes were left out, the delivery was three months late, not all parts were shipped, structure was altered and had to be put back in, the attic was lost due to a sneaky substitution using the wrong structural system ... the list goes on and on. It's been one aggravation after another, involving two companies -- the first was fired and the contractor was sent packing -- and the owner just wants the job done. The pre-fab company, it seemed, never intended to follow the architect's design or the owner's contract with them.