In my experience, the agent has been the catalyst for other vendor referrals including attorney, contractor, inspector, tenants, etc so selecting one that you feel is well experienced in this space will help you to connect more dots.

Our current portfolio:-Florida SFH: Mortgage (includes HOA and PM company) = $2100.

The landlord effectively refused your request, since March rent is included in her 'options'. 

This was included in the initial contract we signed when we put the $1,500 deposit.

many people don't necessarily have the time or skills to do their books*REI specific tax efficient advice to include business structures, 1031, depreciation, deductions, etc.  

If I do end up purchasing a duplex for 299k, I would be living in one for about a year and rent out the other at 1300/month, In which I would still be paying out of pocket for the mortgage (est. 2122/month as per zillow) not including the other expense.

If you're interested, I have a partner network for STR investors that includes those specialties.

Feel free to ask questions and tap into the resources available including the informative BiggerPockets podcast.

'Despite attempts to communicate with the tenant since December, including two attempts to arrange key collection on the 29th, I've received no response.

That takes a good whack out of your final numbers and changes the ball game by a good amount. on a $1000/mo payment its inconsequential but everyone who was buying these low dollar land loans and everything else - ouch.