Are there any verbal agreements or arrangements between the current Landlord and Tenant?

A regular tenant wouldn't be okay with all the excess stuff so this is why I did this arrangement instead of letting the house sit empty earning $0 rent. 

The small details of finish choices, landscaping & staging really tied everything together to bring a home on the market that really stood out.

These are some of the types of questions that will help you determine what stage of motivation (read: desperation) your seller is in, and whether they've really thought through what their options are...It's what you do here that starts to differentiate the ethical wholesaler from everyone else.

All of these costs won't vary significantly enough by property to affect your analysis at this stage so for ballpark purposes you don't have to do it over again for each property.HOA fees will vary from property to property and there's no way to know without asking.

Does anyone know of an insurance company that would insure such an arrangement?

Make sure your tenants are making other arrangements, either on their own or through the Red Cross (their Renter's insurance should provide them lodging, and, if they caused the fire, might handle some/all of the restoration).

LA County is NOT an easy market to get started in, and a move to a more typical housing market could be a good option at this stage in your investing journey. 

The realtor who said she was fine with that arrangement works for a relatively well known firm in the area, she showed up with her tenant, he liked the place and actually contacted me directly for a second showing (he didn't end up renting it, he liked it but it was a bit too small for their needs).  

Far too many get stuck in the "paralysis by analysis" stage, thinking they just don't know enough to get started.