We were able to get the house $20k below market value by securing a realtor that took a reduced commission since we had arranged all aspects of the deal.

Are there any verbal agreements or arrangements between the current Landlord and Tenant?

HOA should have made arrangements with you weeks in advance.

For approval, is it possible to sign some attestation that I will payoff the loan with the first sale then arrange for it to be paid between the close of the first home and the next purchase (will actually have to do this and show the lender or is the attestation enough, or will they somehow arrange it at escrow)?

This is directed at others who have raised investment money in the past. I've raised cash for equity in the past but I'm interested in offering private second position debt that behaves similar to mezzanine debt and c...

This type of arrangement is more of a private investor transaction (versus institutional investor funds). 

Sometimes the sellers will outright request this as a term, but it is a nice option to offer if the sellers are still arranging their own plans or looking for another property in the area and are in escrow themselves.

And, even if the landlord was to remediate, you cannot live there during that time - nor can anyone else, authorized or not.I hope you will take care of your health and your credit (an eviction is a FICO killer) and make arrangements with your landlord to move. 

Are there any verbal agreements or arrangements between the current Landlord and Tenant?

I agree that certain things need to be functional before move in or arrangements made.