Insuring for higher amounts doesn't always raise the premium a ton (for example a $2MM umbrella policy is not double a $1MM policy). 

You usually pay a premium with turnkey because they do all the work: find, rehab, rent, manage. 

Prepaids $595Homeowner's Insurance Premium (12 months) $420 --> I understand this fee.

Yes, your interest rate will be lower, but the Mortgage Insurance Premium (not PMI as many people often call it) is not only a burden, but a huge waste of money (basically paying the FHA's bills).

The less wealthy areas will have risk premiums consummate with the income of the area and consummate cap rates as well.

I wanted to know if I could sell at a premium to an investor/management company. 

They will then try and sell you a policy that does cover all your risk, but I believe that premium will disqualify this property from being profitable. 

The HomePossible loan will likely be a better loan option for you than FHA if you have good credit, and it will save you 1.75% of the loan amount in FHA upfront mortgage insurance premium ($600,000 loan x 1.750% = $10,500 in FHA UFMIP). 

Whatever the highest bid was, they take a 5% premium right off the top. 

In a situation like this you should be charging a premium rent, possible as much as 50% over market, or you should be taking a cut on his business income.