I don't think the fundamentals are really in place.

Fundamentally, @Wayne Brooks is right.

I have NO knowledge of your market but if you have access to properties with lots of equity and the market fundamentals check out then it could be a really good option and you could do less deals to make your money while building long-term wealth by keeping a slice of the pie for yourself.

They are both great at learning the fundamentals.

I have an opportunity to get a mortgage for the first time ever (due to a confluence of positive circumstances such as mortgage rates, my DtoI ratio, my wife working, etc) and am inclined to get two or three, thinking that a good SFD is almost always going to be a good bet if it flows and doesn't need a new HVAC or roof for some time, and even if housing prices drop due to major economic fundamentals going awry such as a stock market bubble burst or our debt problems coming home to roost, or the middle class going the way of the dodo bird ...

So my first question is where is a good place to start reading, in a more general fundamental level, about sdira, solo 401k, ROBS, their respective tax consequences etc...

Here is the deal I would offer:Since it is your capital which fundamentally obtains the loan, not to mention is at risk, you take on the acquisition of the property and finance of the construction.  

I know that a lot of the underlying fundamentals can be applied to anyone, but it also leaves out a lot.

Personally, I tend to think that we have enough other fundamentals going for us in this region (wine, tourism, proximity to bay area...) that it won't have a huge effect, but I'm curious what others think.

First I would choose a market, not based on the people but based on the investing fundamentals- will it be a profitable area, are other people investing there so they can attest to the quality of the area, do the numbers work, do you feel comfortable with the market, etc.