Because lenders often won't loan on a property with foundation problems. 

Do you have a lender that you are working with yet? 

If you have any lenders for DSCR loans please send my way! 

I am not sure what else I can do to be able to locate owners and contact them, short of hiring a private investigator.

living in it while remodeling is the best Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I'd be careful about refinancing, as it costs thousands of dollars in closing costs (lender fees, title fees, recording fees, etc.).

Trying to decide if we should focus on acquisitions in the future that do or dont have a private wwtp:)

You don't need a "mentor" to understand OPM, you just need an investor friendly lender to work with that is a bit more consultative, there are a few out there.

You should certainly start the process earlier than maturity, especially at the very least within a couple months of the maturity date - there can always be things that cause delays and pushes and even missing the maturity date by a couple weeks can have harmful consequences (since it will technically be a default / missed payment even if the lender is OK with it).Also, commercial loans even with the strictest prepayment protections / lockout periods will almost always have at least a 3-month open period prior to the Maturity Date

Check out private schools, church based options.