Trying to get a hold of them on the phone/email has been a challenge as well.

How does one take the owner finance situation to a bank and turn it into a 30 year loan to hold without an additional down payment of 20 percent ?

Next, I would find out who the attorney(s) is in your area that is known for regularly dealing with the Zoning Board.

For a lot of things you can just look up material costs and assume the same for labor. 50% material and 50% labor holds roughly true for the entire project, at least for me here in Milwaukee, your labor cost will probably be higher in the Bay Area.100-125k spread would be tight, even for me here in Milwaukee.

Alot of investors I know from California are mostly going out of state to find deals both to flip and to hold. 

I've been investing in real estate for 4 years, have some buy and holds, did some land flipping as well as wholesaling.

Sales prices and mortgage rates make it really hard to find good deals today.Wholesaling sounds good, but you could make better money working extra shifts as a nurse.You could look for run-down properties as buy-and-holds.

With you wanting to hold it I would not dump 30K+ into it.

Not sure if you were looking for a long-term hold on a two family, but it seems that was not playing out favorably for you. 

You need to have it fully stocked so people can cook while they are there and I tell you it is very important.You need to setup regular services for the hard systems like furnace, AC etc to keep them in top condition.