Looks to have been a homeowner project gone horribly wrong; the slab sits approximately 6" above the ground and is very rough/uneven.

Many have been sitting vacant for months and all it takes is a 25 cent rubber seal to crack and it will fail a pressure testAnother potential issue.... are you getting a loan ? 

I just don't understand sellers who have a property that is just sitting there, and decide to narrow their buyer's pool even further by requiring cash only.

Find out about upgrades, maintenance, on-going problems, outstanding financing, judgements, or liens.Always try to meet at the house when possible to sit down and negotiate the offer.

Nor would I have the time/inclination to sit around waiting for 3 plumbers to come around and give me a bid to fix the burst pipe.  

The loan repayments will come out of your paycheck, so if the property sits empty and you have to cover the loan, where does that money come from?

All my thoughts I've had over the years have sitting in writing, waiting for me to discover.

http://www.latimes.com/politics/la-pol-sac-california-high-housing-prices-20160414-story.htmlThe California Association of Realtors has predicted a mass exodus out of the Bay Area this year, either to more affordable surrounding counties (Sacramento and the Central Valley) or out of California all together:http://la.curbed.com/2016/3/4/11161626/california-housing-costs-migrationBoomers who are sitting on a ton of equity realize they can move out of the Bay Area to retire to live like a king somewhere in the Midwest and purchase their house cash, and Millennials are entering their prime "settle down" years and think $650k for a 1950's tract home is a joke and they can't afford it even if they wanted it.But, they can move to Sacramento and buy a $350k remodeled home in a nice area with great school districts and raise their newborn children.

The more specific the better.The easiest way to get into that conversation is just find a time when she is bored and ask her if she would be willing to sit down and listen to you and ask her POLITELY!

I am happy with a 6-8% ROI each year on a cash deal rather than having it sit in the bank or the stock market.