There are definitely bad apples out there. 

San Diego is a great market long term, don't be dissuaded by a few bad apples.

Either by repairing it or demoing it, you are looking at a huge lift.

To have any meaningful impact on behavior it would have to be an ongoing thing since most tests detect metabolites for at most 96 hrs. 2) while you will weed out some bad apples you will also drive away many many good applicants who will view the cost of this massive invasion of privacy as far to high compared to the value they'd get from living in your rental.

I saw myself appling for a job sheetrocking homes for $10 per hour.

If you have 30 SFH, all free and clear, and your average rents are $1000, which I assume is quite low- you could pay a PM 9% and still put away 25% for capex, repairs, etc and have $20k of income per month without lifting a finger OR selling off your assets. 

Basically, I can bring the drive and the capital, but need help with the rest of the heavy lifting.

The way the platform prefers is that you do a lot of analysis and “heavy lifting” upfront to identify those few individuals that are most likely to result in close, profitable relationships.  

Factor in the capital repairs needed and you may be able to squeeze out more margin for doing more of the lift yourself. 

Thats called investing in a tech stock and hoping it becomes the next google, amazon or apple before anybody else does.Ultimately, you have to decide what your goal actually is and then find something to fit.