Out of state investing is a very challenging proposition. 

But putting all your eggs in on basket can be a risky proposition - especially if you don't have enough reserve. 

For instance, a 15-20% drop in rental rates could turn this barely breaking even duplex (if that) into a $500-$600/month negative cash flow proposition.

We're generally between $25k and $35k, so we aren't selling pie-in-the-ski numbers)We've sold 30 houses this calendar year, none to newbies and many to repeat customers several times over, so we seem to be justifying our value proposition in some fashion.

They do not have the Proposition 13 which we enjoy in California.

As others mentioned, the value proposition is usually not strong enough to attract a good mentor.

In theory if a property cannot produce positive cash flow with a hypothetical 100% leverage buying cash flow with your own money is a losing proposition.

On top of the fact that you have some little baby $300k mortgage on Silicon Valley real estate, there's a little thing in California called Proposition 13 which makes long-term ownership of residential real estate tax advantaged.

That said, I think you may be missing a key selling proposition here.

Perhaps moving the house is possible, even one with a slab, but that is a VERY EXPENSIVE proposition.