I would imagine that if there is a balloon involved (most of my deals do), then there can not be a pre-payment penalty?

If you have the time try to attend one of the local meet ups - I imagine there are quite a few of us in the Bay Area that would be interested in learning more about your strategy (myself included).

They poured the cement themselves, and then took a broom to it.

The previous owner had poured a driveway over the drain field, which was not in working condition.  

Even if you could save money for a down payment, and 6 months reserves, I imagine that 6k a year is too risky for lenders.

I just can't imagine paying cash for a vehicle, unless interest rates were outrageous.  

If an agent lowers their fee that easily, imagine how easily they are going to lower your asking price in negotiations."

We're in Zillow's list of the top 50 metro areas (4th from bottom) but unlike nearly other city there is no information about how accurate they are (median error, within 5, 10, or 20%) so you can imagine how much faith you should put in them.One thing I'd also note from this chart - it lists how many home are on zillow for an area and how many have a zestimate.  

I imagine the convenience and savings of being able to manage it personally is a nice factor.

Although, I would imagine there could be some similarity between states.