Then you'll have a pretty good idea of what you NEED to pull permits for when rehabbing the next one ;) Also, a structural engineer will need to advise the city wether or not a wall is load bearing or not (at least that's been my experience with Orange County CA municipalities)Good Luck!

Please advise/comment/critique on my analysis and question and let me know if I'm missing anything.

An Airbnb person will advise you do that for cash flow.  

I would instead opt for a cash out refi- I worked at one of the big banks here in the U.S. and when it comes to the different options of tapping into your homes' equity I would typically advise to avoid HELOCs due to it being a second mortgage you'd have to account for as opposed to paying off the first and continuing to hold a single loan for primary with refi- while capturing (typically) up to ~80% LTV

I would not advise a condo Airbnb in FL for a first-time investment.

My advise in this scenario is to present the problem with the neighboring property immediately.

If you don't know you shouldn't charge, although some would advise you charge and let the tenant complain. 

Also realized that the supposed recent sales that should have been used as comparison for the same property was as far back as FEb/Mar. what should I do about this please advise.

I wouldn't be able to advise you on this without exploring the questions/ going further as seen in paragraph one. 

My advise IS the correct and best advise you will ever get. you accepting this advise is to YOUR benefit.