Next time, also get estoppels with the seller and tenant signatures so you're all on the same page about when rents are due, how much they are, and how much security deposits are owed.Take it as bitter medicine.  

Its not so much about the signature in this case rather than papering the file to show the courts (if needed) that the landlord was responsive to the tenants concern with a reasonable solution to protect them. 

When I execute a lease, the only way my signature gets on that document and the only way the keys get turned over is when I have all monies.

I'm tired.And I'd make their new lease contingent on the signature of the departing tenant agreeing to terminate and duke it out with the other tenants, regarding any refund of their portion of the security deposit.Your lease agreement time frames are odd.  

. - I will have to sign a non-disclose and non-compete with a two-year lifespan starting from the date of signature.

To make it even more fun, there is often a single family member that doesn't actually want to sell (but his signature is required), wants to 'keep it in the family,' but doesn't have the credit/assets/income to actually make that happen, so he might just be difficult while entertaining his delusions.

With RHA, you'll not only need RHA's approval, but you'll need the tenant's signature on the form before providing it for consideration to RHA.

As long as the major factors are included on it with both signatures I'll save myself a lot of trouble and not get bogged down with all the extra wording and all.  

So she knows she has no security deposit and it is in writing with her signature.

Don't bother with certified mail that requires signatures.