The more cash flow, the higher risk the property is in this market.

TBH you should probably build out your own that includes your own investment criteria rather than use another investors who has different goals and most likely invest in a different market with different systemic and asymmetric risks.

SFH are becoming much higher risk as opposed to multi units that are valued on rental income.

But if they have good, steady income and good Landlord references, they may be excellent renters that will stay put for a long time because they can't qualify to buy.There's nothing wrong with taking "risky" tenants as long as you mitigate the risk and have solid processes in place for when they fail.

Paying off my house in CA has minimal risk, whereas putting a large chunk down in an overpriced market is a big risk.

Plus it mitigates the risk of only you having the financial burden of financing by yourself and develop relationships Let me know if you have any questions.

Should I take a $5-6k risk and drill a well? 

Not worth the risk IMO

I feel as though I’ve learned enough to conquer any challenges I may face, but when time is money, I think I’d rather not take that risk.

That would help with understanding the risk tolerance.Gastonia is a popular place for investments where she would be able to purchase cash.