Is there a due in sale clause?

Live in Boiling Springs now, but I work in a sales job that covers Charlotte and Boone as well.

Do I need to tale to a professional that handles 1031 exchange before listing property for sale?

So, I am a bit (Outraged....oooh that sounds to harsh) dismayed, that I am looking for great videos/articles to use on my FB Business page promoting using "Cash Buyer" option for a home sale.  

We have also decided that this particular property will make a better flip than rental, so we will be listing it for sale when completed.

The buyer turned out to be a flipper, had a for sale sign outside in Jan 2007, believing realtors the property is worth $850K.  

I had done a couple of deals in Southern California, selling the last one this last September and just had the proceeds from that sale sitting in a Money Market doing squat. 

We will have about $300,000 free and clear after the sale of our home.

County Tax Foreclosure sales are Public on my county's website.

This particular property is a Short Sale in Cincinnati, OH and has about $2k (1 years' worth) of past due taxes on it.My contract with the Seller reads, "At closing, Seller shall pay or credit on the purchase price (a.) all real estate taxes and essments, including penalties and interest, which became due and payable prior to closing...."