It may be true that the guy with the 4 duplexes will have to scramble if things go wrong, but that's more a feature of overextension than it is an indictment of the multiple property system.

Assuming that's close to the right numbers (and if you think i'm crazy, please say so), have other investors in Baltimore found central A/C to be a key feature, and provide a return on investment in cashflow and/or resale worth the upfront cost?  

If a salient feature of real estate investing is being able to actively influence your investments, why is completely delegating everything to a company the only way to outsource any of the burden of managing a property?

This is one of my favorite features of Bigger Pockets especially for asking specific questions.

If you are unfamiliar with design features in this price point in your coastal area of FL, might I suggest you hire a consultant or designer (make sure the designer is an investor at at minimum, investor experienced as many designers love to pick expensive name brand stuff that you could easily make the same look at half the price).Hattie's list is good and outdoor kitchens are a must in coastal areas like yours and mine.

Even in a small market like Montana, there is always another deal down the street to analyze.In SFR sales, you're always selling features like a view, a gourmet kitchen, a garden bath, walk-in closets, etc.

Hm I'm studying Buildium's accounting features.

The point of those features in those loan programs is to encourage mortgagee participation in those markets.  

Being able to download transactions is certainly a great feature.

Also if you hold onto them you "might" be able to demand higher rents, but honestly in my experience no tenant has ever mentioned windows as a feature they were looking to pay more money for...