He says it’s mandatory that I show him taxes paid and insurance on the property.

Non-required, cheap insurance is worth having. 

I advise them on how to build credit or direct them to Insurent and help them with other options, but respectfully tell them I won't show them the apt if they know from the start they wouldn't qualify for it.In Brooklyn we say: "credit is king!".

All of those things insure a strong market and growth.

I was wondering if there is a way for me to pay homeowners insurance as if it is 1 four family home, rather than 2 separate homes.

Granted this often covers roof repairs, exterior insurance, lawn care, sewer and some other expenses.

The only bills the owner has is taxes/insurance, as well as property management/maintenance.My question is how to evaluate this deal; Do I base the value solely on the lots, or do I include the entire $500 which includes lot & trailer rent? 

You just received a copy of the letter because you are the Owner.The PM should be filing a claim with his insurance carrier.

Also, making sure you home owner's insurance is setup to cover the rental onsite and having adequate coverage will take you a long way.

In this tight inventory market, it's far easier for you to find a 70% ARV home than it is a 60% ARV home to have room for an assignment fee.Obviously, we do it every day in both categories, but I'm also a Licensed GC with dozens of crews, a full office team including a rehab manager, etc... so it makes flipping very easy for us.Flipping is much riskier from a time, money, rehab, construction, crew, theft, vandalism during ownership, lawsuit, insurance, holding cost perspective....but we still do plenty of them.We used to be 80-90% retail flips.