Florida Duplex renovations!! Do I need GC? And Permit for refinance (or to sell)?

[Halil C.]

Hi all,

Got a duplex recently in Ft Lauderdale, it is my first primary property. A couple of facts: 
a) Not planning to sell it anytime before 5 or 10 years
b) Planning to refinance it next year or so, after the renovations are over
c) Planning to use the unit with backyard as short term rental

- General contractor gave me a very high number. Thus, I want to work with each specialized company separately. 

I have a few critical questions:
1- Do I need permit for kitchen and bathroom remodeling (which includes changing the layout within its boundaries without expanding it)?
2- Do I need permit for adding another bedroom? Would it affect refinancing or selling it? Some say that I can sell it "as is"
3- Not having permit for these work, would it affect whether I can put it on short term rental?
4- Finally, can I have the permits after the work is complete? I learned that it takes time to get permit so maybe we finish renovations first, rent it out, and then get permit?
5- Do I need to have an umbrella insurance for these individual workers/freelancer or companies, just in case? Or if they have their insurance, that is enough?

I know this is a long post but I really appreciate any guidance and help.

Anyone in Ft Lauderdale/Miami area who knows a good contractor, I am still open to that option. And actively looking for AC companies, kitchen, and bathroom remodeling companies.

Thank you,
Halil