Typically in a substantial loss, the lease is terminated automatically, the insurance covers your loss and the tenant is on their own for their losses including loss of housing. 

We did a rate and term refinance (no one would do a rate and term in their right mind today but our loan was a matured balloon) on a Fannie Mae loan and did a HELOC behind it.

I plan on making ours where the buyer has the ability to terminate it (no worries with me) but any properties they purchase that were shown by us will be enforceable for like 30 days.

It also states that we can terminate the lease if mold is found.

This gives you the sole right to buy their house.The assignment agreement (between the back-end buyer and you)  says that you are passing along YOUR sole right to buy that house over to the back-end buyer, as the cash buyer then steps into the contract and you (kinda) step out of it.You know when your bigbutt friend sits in a chair for 3 hours, he gets up and you sit in his charge and you feel all that buttheat terminating from that chair?

Make sure it explicitly explains the process for termination if you are unhappy with their services, especially if they violate the terms of your agreement.3.

Our hope is that we could hold it long term in order to have a rental house in our area. 

@John Warren and @Jonathan Klemm thanks for the Mentions.The City rececntly terminated it's "Eazy Permit" process and replaced it with the "Express Permit" process.

The notice period changes based on how long a tenant has lived in the space, so you may need to give up to 120 days notice of a change in rent or termination of a lease if the tenants have been there 3 or more years.

You can use your favorite search engine for "terminate lease south carolina" and do some reading.