@Steven Liu  I use the recommended REI GUARD Insurance. 

.… 1-Haul in dirt around foundation install window wells 2- cut back trees that are too close to the house 3-clean gutters forget gutter guards most if not all do not work for various reasons 4-increase the  size of gutters, make sure gutters discharge  10' , I buy black drain pipe burying it discharge far away from the house.5-Sump pumps is the last thing to do. they are noisy.

Some have very good guard dogs as resident managers on the lookout for STRs.

I had a tenant like that, he was a guard at a casino.

You can also add splash guard clips to the shower wall to accept the shower liner. 

My tenant turnovers tend to wipe out months of rent, so I'm trying to guard against that if I can.

E&O Insurance is a closely guarded thing. 

Ahhh yes the elist old guard attitude "For real investors it offers nothing".

There is always someone out there looking to charge way more than a job is worth hoping to catch them off guard.

Primarily it is to guard against a loss of income by one of the tenants whereby my standards would protect against this financial loss to me because the other person would be completely able to pay the rent (in theory).