I also own a plumbing and a construction company, so if you have any questions please fill to ask.  

I own several Airbnb's in San Antonio as well as have a company that manages them.

I would seriously consider at least getting a quote from your insurance company and then shopping around.

In other words, a company looking for qualified investors gives referral fees, but a nonrealtor knows some qualifed investors who may be interested and wants to know if there is an agreement for that.I believe there is a name for that, and are there examples?

Multiple, billion dollar companies are investing substantial amounts of money into our area, such as Intel, Google, and Amazon.

You're in good company.

This year we are purchasing about 3,000 leads per month and skip tracing all of them so we have narrowed it down to a few companies we feel comfortable referring. 

According to case shriller (reputable source) the return on San Diego small residential buy n hold is number 3 in nation for this century.  

In reality this guy is unknown, and seems to have a sketchy reputation.

A landlord, the local grocery store and the utility company etc have no business whatsoever knowing a tenants  SSN and if I were you avoid collecting them.