Loan amount left is $132,000.If we list it, we can sell at $205k and assuming 8% closing / realtor / concession fees, the revenue would be $188k. 

I'm seeking some insight and advice on navigating a situation with a duplex we are closing on in a few days; one unit is vacant, and the other is occupied.

To trigger this exception, you must meet three criteria:You must sell your entire interest in the underlying passive activityYou must trigger a tax event, meaning that you must sell your interest for value in a fully taxable transactionAnd you must sell your interest to an unrelated third party, no family or close affiliates.Source Link

This can be very expensive and is usually the worst choice because you can't justify the cost.2.

After 3 years we had acquired 3 duplexes and one triplex with 100% occupancy and clearing close to $2000 a month. 

And any short sale offer will have to be close to market value.Years ago, after the great settlement agreement with the big 5 banks, those banks were making mass offers of discounted pay offs on seconds.

This affordability factor, combined with the potential for long-term appreciation and steady rental income, makes older low-rise condos a compelling investment choice for savvy investors looking to diversify their portfolio in Miami's real estate landscape.BUILD EQUITY – Investing in older low-rise condos also allows investors to capitalize on potential renovation opportunities.

I would disagree with just hiring someone hourly but that is certainly a choice; at $150/hr you will not be getting experienced advisors that can do higher level deep work and real planning.  

Do you have to start making payments right away when you close or do they give you time to get the construction complete?

I have seen before 1031 buyers lock in 3 choices but not get some material while under LOI to see if property is viable for cash flow returns and for financing they would like.