Without knowing more details about the specifics of the project being proposed as it relates to your property, it's hard to say if there are any obvious big red flags that could negatively impact your property's future value.That being said, I would try to find out as much information as possible about the new apartment building's design and layout - the two big things I would try to ascertain would be the location of the garage entrances/exits, as well as the location of any outdoor amenity spaces (pools, terraces, dog runs, etc).  

Way too many Red Flags and lack of transparency.

In this day and age, not having a online Prescence and clearly documented track record is just a huge red flag

even suburban submarkets are red hot right now in miami like leisure city, homestead, florida city you can still get infill lots one of the last few places in miami dade county right now. rezoning and variances you can do even better. if you are limited on capital ground up construction and land might be something to consider in miami in these submarkets.

That’s what I see  So thats the contradiction is that. and thats the red flag for me....they live a debt free life but have a car payment.

What red flags should I look for that would lead me to see a property that has been sitting as an “unwise” investment

Just some food for thought on your hunt for the Red October.Are you looking hire an ttorney To teach you creative strategies And recommend Creative strategies  to you, or are you looking for a chain dog to implement your creative strategies?

If they are not, that's a red flag.     

The more I’m thinking about this the more red flags I’m thinking of.

There will be red flags that jump out at you...obvious drugs, poor/no work history, etc3.