But it was, and yes, I signed it.  

If I buy a property for short term rental and do a cost segregation study to speed up depreciation, can I later decide to convert to a primary residence?

In connection with its duties, Qualified Intermediary shall be protected for acting or refraining from acting upon any written notice, request, consent, certificate, order, affidavit, letter, facsimile, email or other communication or document furnished to it under this Agreement and to have been signed or sent by Exchanger or any of its officers, attorneys, or other representatives, provided, however, that any instructions relating to disbursements of funds shall be subject to the provisions of Section 3.4 above and the Disbursement Instructions shall be signed by the taxpayer or submitted by the taxpayer online via the Software."

I really appreciate any input and thoughts to help gut-check my matrix before signing the PSA.

Typically land costs will decide whether it's feasible to build new. 

As a person who is new to Real Estate and Real Estate investing, is it best to save up cash or do a cash out refi on your personal home to purchase a 2nd home (1st rental)?  

This type of exchange provides investors with a way of increasing liquidity and diversification of their real estate investments, while deferring very costly capital gains and depreciation recapture taxes that may result from the sale of properties.

If you consistently analyze properties, recognizing a good deal will be much easier when it shows up.

(Everything from early research to closing and listing your STR and getting money coming in) I'm always looking for ways to step up my game as an agent that specializes in helping out-of-state investors buy STRs in the Florida panhandle/Emerald coast.

I was already well into the remediation policy after Helene on 4 units, now picking up the rest of the pieces.