It appears this might be excluded from insurance coverage, and I am trying to look through disclosures and contracts about lead issues.  

I believe disclosures / marketing materials / compliance etc it’s recommended not to be licensed.

You need to consult with a lawyer, especially if you didn't sign anything acknowledging the property's lack of habitability and the seller's disclosure didn't mention it. 

Look at your “closing disclosure” the next time you receive one.

Full disclosure: I am the tenant in this situation.

A seller's disclosure will ask if there are any property boundary disputes.

To protect the purchaser of the wrap-around mortgage, Texas Senate HB 43:provides for wrap payments to be held in a constructive trust by the seller for the benefit of the buyerestablishes that anyone collecting or receiving a payment from a wrap borrower in connection to a wrap mortgage owes a fiduciary duty to the borrower for the paymentsdiscloses the nature and risks of wrap transactions to buyers and offer consumers the right to rescind transaction/agreement when disclosures are not made timelydefines “wrap mortgage loans” as a residential mortgage loan:made to finance the purchase of residential real estate that will continue to be subject to an unreleased lien that attached to the property before the loan was madesecures debt incurred by a person other than the wrap borrower that was not paid off at the time the loan was madeobligates the wrap borrower to the wrap lender for payment of debt, the principal amount of which includes the outstanding balance of the debt and any remaining amount of the purchase price financed by the wrap lenderclarifies that a wrap mortgage loan may only be closed by an attorney or title companyprevents “house flippers” from registering as financial service providersprohibits a person from making wrap mortgage loans unless the person is licensed or registered to originate or make residential mortgage loansThe new law goes into effect on January 1, 2022.

I am familiar with buying/selling FSBO and have contracts, Seller's disclosures forms, etc.

You should alsohave a grasp on what other loan rules are, especially loan to values and disclosures this is critical to stay out of trouble.

Part of the reason why the first $1.8B lawsuit happened was because of poor disclosures in that state.