Also, what kind of liability or how much extra insurance do you need if you offer kayaks and life jackets as an amenity?

I think the code says 1/2-3/4"of jacket inside of a box.  

Not like a yellow jacket sting but still not pleasant. 

You might find yourself in deep waters with no life jacket and not knowing how to swim.

You can also go to the city and pull the property jacket which outlines everything that has been done to the property in it's history.

And I find tenants don't have that expensive belongings anyways, unless something happens, suddenly they have $1,000 leather jackets, and $1,000 high heels.

As @Jay Hinrichs pointed out, a lot of what you noticed as being 'deceptive' is actually just the industry standard for property jackets.

I sent a gentle letter to that owner asking if they could talk to their tenant. 2 weeks later, haven't heard back.Then on Friday night, my tenant called me to tell me the neighbor stopped over, was very aggressive - seemed unhinged and during the conversation, pulled a gun our of his jacket and pointed it at my tenant.

  #2 Dress very casually like basic jeans, t-shirt, jacket. #3 Do not try to make friends, instead be cordial and respectful #4 Like Jay Ballman said definitely hire a property manager and never reveal your secret identity as the property owner

Running new wire to replace knob and tube, cotton jacketed, or NM can be tiring.