Since the lease was with both then you need to make the check out to both, to do otherwise would be making a legal determination which is what the domestic court is for, and where they can take their issue to resolve. 

Is there any legal guidance suggesting I can or cannot do this?

I am not going to say there is a best lending model, but brokers legally can not be paid as much as IMB's, and I tend to be cheaper in more situation than not when comparing a loan estimate from an actual lender. 

This should not be construed as tax, legal or financial advice.

You will find many recent posts from investors who have lost all of their syndication investment, and then talk about bringing legal action against the syndicator.

Legally speaking, if you have agreed to an installment sale, I'm not sure if the stepped-up basis is applicable.

At which point am I legally allowed to relist the property for rent again?

Here is a reference that explains:https://www.nolo.com/legal-encyclopedia/intestate-succession...2.

Selling or Transferring the Deed: Legally, the husband can transfer or sell his ownership interest without needing the wife’s permission, as she is not listed on the deed.

Like most states, Georgia gives you the legal right to enter for inspections, repairs, or showings.