Do the math at a 6% loan rate.There's a reason many apartment buildings have been converted to condos and sold.

I would only do on 1+ acre properties.

Either way I wouldn't do one in your area that wasn't driven into the ground.

Hated it so much, that they gave me variances that nobody had gotten in 20yrs in the area to knock it down and redevelop the site.

I think all of your suggestions are great possible ideas to do this deal! 

Quote from @Nadine Wallace: You can do simplisafe with/without Wi-Fi, but you will need cellular service.

HA/ABB which do it automatically. 

See what the $19k was for first, it may have been neccessary, but still that does not make it ok for them to do it without a signed CO.You can ask an attorney a few questions using sites like Avvo or Rocket for not much $$$.

Everyone has different personalities and ways of doing things.

I've said this before, but I would contend that we are in a "What can you do that is really hard?"