Every first time homebuyer is advised to avoid a building with foundation issues. 

For SFH New Tampa is good if you're looking for newer builds, I also recommend Carrollwood and Citrus Park for SFH as well as the others I stated. 

I'd look at at least 3-4 family lots at a minimum for economies of scale. the price of land in miami is so high it makes single family home building nearly impossible. flips aren't worth it.

Include your logo or a professional image to build credibility, and make sure your contact info is easy to find.

I'd strongly recommend seeking out other purely passive accredited investors and focus on building real relationships.

The biggest is going to be whether the HVAC is properly sized for the building.

My 2nd duplex was a new build in Indiana. 

With that said, there are factors that come into play there.  

I would just factor what you feel their portion of the water bill or whatever utility should be based on the monthly average and charge it as additional rent.

Find properties such as duplexes, triplexes, and small apartment buildings on BiggerPockets Marketplace and local listings.