When filling out the LLC application it doesn't allow an out of state address for the registered agent, indicating I can't be the agent as I live out of state, but I read elsewhere the agent can be either a resident of Florida, or somebody authorized to conduct business in Florida.

At its core, it’s just long-term rentals where part of the tenant’s rent is paid by the housing authority.

It has just become a famous book that has inspired so many people to become successful investors over the years that nearly every guru and RE coach recommends it.That said, the author has always been a bit of a nut job :-) If you take to heart the way he "re-defines" already well-defined accounting terms you'll sound like an idiot speaking to a bookkeeper or CPA.

Every housing authority has its own compliance quirks and if you're not factoring those into your numbers upfront, they eat your margins fast.

Also, require the Corporate entity to provide you with identifying AND contact information for each person authorized, and their start/end dates. 

In my market (CA), before a first time Section 8 tenant can rent from you, they must attend a Voucher Holder class run by their local Housing Authority.

If you can prove the market rents should be $1400 the Section 8 housing authority should be paying that.

It sounds like these are all in the same county (property taxing authority) and the rents and other expenses except for financing costs are only guesses.In this case your answers aren’t property specific. 

The sibling that has to authority over the home is open to selling it to me, but when I talk to my acquaintance, they told me the oldest brother is very mixed and iffy on how they do business.

I decided to look up the author.