Since it wasn’t your primary residence you lived in for 2 years, then no section 121 exclusion.  

You will learn much more, much more quickly speaking to experts in this specialty field than chasing down rabbit holes on the internet.There are rules associated with keeping the tax-sheltered status of this money, largely around keeping things exclusively for the benefit of the plan and avoiding intersection with yourself, lineal family, or family businesses. 

So if the seller has a signed agreement with the agent stating that agent has exclusive rights to sell, that agent will get paid regardless of who sells it.

When it comes to selecting a realtor to work with some may ask you to sign an agreement that you work with them exclusively.

But, if this was an estate with no heirs and it would need to be publicly marketed in the newspaper for 3 weeks to find missing heirs and if no one responds to that ad, the sale can continue and judge will sign off etc. what do you need to do with probate in regards to real estate?

Check out the 121 exclusion with your CPA. 

They signed with an agent and are fully exclusive currently.

Many areas will have a local business newspaper or site.

The newspaper?

The city pretty much exclusively issues licenses for up to 2 unrelated now, and they only allow about 25% of homes in a neighborhood to be rentals.