HiI own several multi family buildings in Central / North Florida and for example on an older duplex I pay $700 a year for insurance, which I feel is a good deal. 

Even legendary billionaire investor Warren Buffett, with all of his endeavors into energy, insurance companies and holding sizable stakes in companies like Coke and Wells Fargo, still calls his own home his best investment ever.

I assume that I can take possession (change locks etc) and perform structural repairs sufficient to bring it back to habitable standards but my question is does that include sprucing up the property itself ie tree trimming grass cutting and the like to maintain neighborhood norms?

Holding costs are things like mortgage payments, taxes, utilities, insurance, HOA fees, and anything else that pops up while you own a home.

Of course, aside from the standard tenant placement, rent collections, repair management, those are a given (right?). 

There is no standard way to measure square feet unless your state by law has a predetermined method. 

They very well could be right that it's a rough area by their standards (subjective to each investor), but there is a market for that type of neighborhood.  

Some of my costs just to maintain, and these are just estimates as I dont want to look up the exact amountsMLS = $1,000E&O Insurance = $1,000Board Dues = $1,000Sentrilock = $300Showing Service = $300Continuing Education = $500Licensing Fees = $300

I can't confirm how much taxes you will owe (not a CPA, you should confirm this with a CPA) but you will be able to deduct prorated portion of all expenses on the property (mortgage interest, property taxes, insurance, property management fees, repairs, etc.) and then whatever is left will be taxed. 

Government ID verified On top of all of that I use a separate Standard Rental Agreement written by my attorney to be signed electronically by all guests.