But I know I'd have been happy if my home came with Nest thermostats, Dropcam(s) in the nursery, wireless mesh pre-tested for that specific floorplan, one of those doorbell cameras, etc.

Home inspectors normally do not do destructive inspections - digging up yhe ground would be somewhat destructive.And plumbers send a camera into the sewer lines, from either a clean-out, or they remove a toilet to send the camera in that way.

One last piece of advice I would give you is get a good camera system.

Install cameras and give any evidence to the police.

You are going to have to find a reputable plumber in the area with a camera and have them look at it and show you exactly what they find.

But I do recommend purchasing a nice wide angle camera.

I'm more likely to just wear a baseball hat with a camera on it for the whole year -- I'll talk to my accountant, maybe get a new one... 

But he does not care much for social norms or cameras in the building and keeps doing things that are either violation of CC&Rs or bothersome to HOA and neighbors. 

I would never play a recording back to someone who did not give me permission to record the conversation.I am always thinking about the video cameras in my office where I have two microphones connected to the camera.

Waiting on City Occupancy inspection and finish installing security cameras.