I would wait close to lease renewal when they are enforceable.Otherwise the old lease and its rules are valid.

You can still negotiate with the second buyer as a backup offer but their offer would not become valid until the first buyer backed out and the backup offer would then become the primary offer.

I''m wondering if I'm applying my own very conservative financial ideals (I don't carry any consumer debt, pay cash for cars) on my applicants or if I have a valid concern regarding ability or willingness to pay rent down the road. 

The judgment isn’t valid’….

I’m an agent and I know the off-market wholesaler world is increasingly scrutinized but I see it’s validity in increasing measures for investors.

The newer property will typically have less issues and repair costs than something much older and there may even be a builders warranty in place for further protection, also ask about tax abatement on the property as new construction with a built in abatement will greatly reduce your out of pocket ownership expense for the length of the abatement  

I have a bunch of reasons for this target but for the purposes of this question, let's just assume they are valid reasons and the right choice.  

Borrower must have a valid Government approved identification card7.

Especially in these times of covid, it would easier to evict someone for not holding a valid lease than it would be for non-payment of rent.Of course consult your attorney and be sure you understand your local and state laws.

@Willnelis Miranda If they are living in the home, it should have a valid CoO in place.