The offer I received is a 9% interest rate on a 5-year term, resulting in a monthly payment of $726.

The faster track on rentals  (cash-flow wise) is to do short term rentals like AirBnB, etc….

The rest will be leased.How do I determine and analyze a potential location for this development in terms of potential lease rates, vacancy rates, potential area growth, post construction value, etc?

Which one (usually, and I understand it's not simple) has a better resale and long-term potential?

Fannie/Freddie have more restrictions in terms of experience and net worth to qualify.

Are these loan terms competitive?

I work with The Short Term Shop and they specialize in helping investors purchase and learn to run and manage their str's. 

I’ve been thinking going the second home/ mid term/ str route. another thought I have is venture further into a rental property but I know with rates, finding a deal that would cash flow would be tough. 

You can also usually get a conventional loan with more favorable terms if you are living in the unit for at least a year. 

Zero cash flow translates to negative cash flow in the short term because you have to maintain it.