(gross rents $4900; 8% PM; mortgage+insur+taxes = $3600/mo).

Includes a single family home (4 br) which was divided in two sections one of which is being rented.

I'd sell because you are reaching the time when you lose the cap gains exemption and that $24K would take over 2 years of renting to get back.I had a condo that I owned for a long time and I sold it despite it being paid off and having long term tenants. 

@David Spurlock from approximately 2012 to 2016, you could buy a depressed valued Class A rental and rent it for immediate cashflow in many parts of the country.After Class A property values recovered, investors moved to buying Class B rentals - but used the same assumptions they used for Class A rentals.After Class B property values recovered, investors moved to buying Class C rentals - but used the same assumptions they used for Class A rentals.

I'm looking to sell my first home, which I've been renting out for the last 2 1/2 years -- I first contacted my property management company  for seller services, and they initially wanted a year exclusive selling rights.

The BS discrimination claims (you won't rent to felons, and blacks are more likely to be felons, therefore you're a racist) will go away. 

Long-Term Rental Rules: Even though my properties are long-term rentals, are there any tax benefits I might be missing if I occasionally rent them short-term?

If you are open to value add strategy, small multis have potential for not only traditional forced appreciation but also the ability to see major rent increases.  

The property, though is not beach front, nor does it has ocean view, is just a short drive from some of the best beaches in the west, which are great for surfing, snorkeling, SCUBA diving.In the 1.21 acres there is a main single family home (4 br) which was divided in two sections one of which is being rented.

Don't let them choose for you.Just inspect what you expect....Also I would talk to housing office in Memphis to get a feel of how many people are on the Section 8 waitlist, what kind of rents they pay, what zip codes are they targeting, see if they have any stats about how long tenants stay and average rent.While a lot of people try to look at google street view to get an idea of the neighborhood, there is no substitute for visiting in person.