Those sound promising as they can detect and notify owners and property managers about water leaks.

Tenant acknowledges that Landlord, or his agent, upon commencement of tenancy at the above described premises, has installed or caused to be installed __________operational smoke detection/alarm device(s), __________operational carbon monoxide detection/alarm device(s), __________operational combination smoke/CO detection/alarm devices and has shown Tenant their operation.

Some are probably telling the truth, but a landlord is not a detective, judge or jury.

The septic tank has a built in sensor that detects when it’s ready to be pumped.

They could have sensors that detected me blowing on them (ie, the appraiser mentally took note, consciously or otherwise, of the race of the "homeowner," and that tainted the results).

Call your nearest large police department and ask to speak to a fraud detective. 

Tenants pay %100 percent of the bill and you know exactly who is using what, not to mention the leak detection and high/low usage reports to have complete control of your properties finances. 

Today during insurance quote, one of the agents detected a claim of damages for over $100k two years ago and asked for clarification, which brought up more potential issues to our attention.

Get a private detective and prove it.

. ($5 per day) ____ Unauthorized Occupant Fee - Individuals not on the rental agreement are staying in the unit past the period allowed for guests and without the approval of the landlord ($50) ____ Unauthorized Pet Fee - Pets/Animals not on the rental agreement have been in the unit without the approval of the landlord ($50) ____ Smoking Penalty Fee - Smoking in the unit or on the premises by either tenant or the guests of the tenant ($50) ____ Smoke Detector or Carbon Monoxide Detector Tamper Fee - Detection device in the unit has been tampered with and is not functioning (Up to $200) ____ Property Damage: _____________________ ____ Service Charges - $20 for each legal notice served related to a violation, such as "Notice to Comply" or "Notice to Pay Rent or Quit".