However, I'm not sure how to do that with limited funds saved up. 

SF has a limit of 90 days per years for AirBNB in the city otherwise I would keep it and short term it all year long.

There were challenging grading issues and limited access from the street to bring in utilities.

Or is it limited to 1 property per individual/LLC per year? 

If there are two borrowers, then of course if a POA is used it would be limited to one borrower...If both borrowers were available and/or decided to attend they would both sign the loan and therefore no POA.2.

Quote from @Stuart Udis: The natural buyer of the entry level SF homes have limited cash and therefore the biggest obstacle they face is funds to close.

We just discovered a crack in the concrete slab foundation that is a borderline major problem:- It is a vertical crack about 1/8 inch wide that is at least 9ft long, which is causing a 3/4 inch drop in the flooring and some evidence of old (luckily) limited moisture and termite intrusion. - BUT, it also appears old and probably a symptom of the original house settling.

The only way that works is if they have fully connected utilities and it is sitting on some kind of foundation and not on a trailer.Some folks think they are cool, but you really limit yourself on demographics.

Is there a housing shortage or is there really a problem with the BARRIERS caused by productivity, land use, zoning and mandates that limits construction?  

You are currently sitting in Los Angeles's entertainment mecca and Mid Term rentals/30+ day rentals are a great alternative to the STR limitation.