I would be looking for someone who has liquidity in case you need to pivot, similar time horizons, and discuss expectations about roles and responsibilities. 

Many people are so entrenched in their ideology that you're not going to change their mind and it's an exercise in futility to argue with them.

Last question, may be a silly one but just so I better understand, what is my role as the agent in this scenario if I'm representing both parties in this scenario?

It sounds cheesy, but the best way to prepare is to work with a friend or two and role play.

In other areas, that may not be the case and being prepared to carry holding costs plays a role. 

Is there a role for a buyers broker on transactions where the seller isn't represented?  

Sounds to me like both the seller and their realtor exercised poor judgement by signing a contract with a breach clause, rather than inserting terms in the purchase agreement that would allow them to continue to accept offers and for the buyer to be allowed the option to match or exceed any higher offers.At any rate, sounds like @Tom Gimer has some solid advice.

Florida's financing extension is in paragraph 5: EXTENSION OF CLOSING DATE:(a) If Paragraph 8(b) is checked and Closing funds from Buyer's lender(s) are not available on Closing Date dueto Consumer Financial Protection Bureau Closing Disclosure delivery requirements ("CFPB Requirements"),then Closing Date shall be extended for such period necessary to satisfy CFPB Requirements, provided suchperiod shall not exceed 10 daysAlso, if the financing period passes and the buyer's don't opt out, this would apply: v) If Buyer is unable to obtain Loan Approval after the exercise of diligent effort, then at any time prior toexpiration of the Loan Approval Period, Buyer may provide written notice to Seller stating that Buyer has beenunable to obtain Loan Approval and has elected to either:107 (1) waive Loan Approval, in which event this Contract will continue as if Loan Approval had been obtained; or108 (2) terminate this Contract.

I can purchase a property on lease to own, airbnb it out, exercise my option, and purchase the property to convert it to longterm. it would seem that you all are thinking on a much smaller scale than me about this specifically and placing your limitations onto me.  

It's tempting to go the passive route, but I'll definitely try to take on a more active role, and see how I can go beyond the minimum to make my units stand out/work better in the long run.