I'm new to RE investing as well but the more I learn and do research on successful investors the more I realize that when they analyze a potential deal they've answered the questions above so well that its incredible easy to spot bad deals, as most properties are. 

Allapattah has major potential as its still closely located to popular spots that people want to visit but that is still a few years out until its fully established as a safe/nice neighborhood.

I feel like we may be in a favorable position to leverage this home and potentially begin a real estate portfolio and/or generate income, but that's merely a guess on my part.

Acquiring homes that have ADU potential.

Though I assume there's some seasoning potentially needed for that or it might be too easy to trace back 2 levels and sniff that out?

Eventually we plan to build one or two additional SFH's as well as 4 STR cabins on property B as well.If I can make the reno on Land B work and release Land A, we could potentially resume the build on Land A.

First - it doesn't even seem like you are sure what taxes you are or are not paying for.You should verify this before bringing up the potential situation with the mortgage company.You can review your escrow balance and see what taxes were paid during the year.

Considering a HELOC for that land down payment is a solid move with 70K in equity, offering flexibility and potential tax perks.

Seeking valuable advice on cities within these states that show promising potential for growth. 

I know nothing about raw land and its potential.