Now, three years later, my tenant reported cracks in every room—paint cracking and full-line cracks in the bathroom, living room, and bedroom (walls, ceiling).A drywall contractor looked at it and said it’s normal wear and tear, but I’m concerned since it’s in every room.

Your not correct under many different circumstances.First property tax is 1.1% (fairly safe) with 2% annual increase (prop 13).Next expenses include a lot more than property tax and interest. 

The one who thinks that they are masters of the universe in EVERY area of life, has 30 different businesses, claims to be fit as a fiddle, with a life in perfect harmony, shows off huge toys, has 30 different businesses, including selling their time by the hour to provide coaching... this person is not running a real estate syndication business.

Despite facing setbacks, including a year-long renovation process, I tackled the repairs, improved the interiors, and addressed all concerns.

.: Quote from @Patrick Roberts: For the late payments, contact the servicer that reported them late and ask them to remove the late payments from their reporting (after explaining, etc).

The other groups I'm in are always reporting the difficulties of getting claims paid for.    

Follow all safety requirements your Insurance Company plus city and county require.This usually includes childproof access and alarms.

If the landlord or their employee did the work themselves, they must include a description of the work, how long it took, and the hourly rate they charged.

I am particularly interested in turnkey properties and single-family rentals, but I am also open to exploring other options, including duplexes and different investment strategies. 

(myself included).