Can I REFI one of my conventional mortgages into a DSCR for that piece of debt to fall off my debt-to-income?

If I was to venture a guess (just a guess), the Fair Housing Act might fall under the federal governments power to regulate "interstate commerce" because the buyer or tenant may be coming from another state.

Please let us know if you need any assistance with this as we're a local mortgage brokerage located in Fall River MA.

I was in particular referring to discounts on houses that may fall into ocean in near future. 

You can request PMI to fall off your loan once you hit 80% LTV. 

At a tax sale in fall 2014, one conglomerate bought over 6,000 properties as a "blight bundle". 

This would fall under the delayed finance exemption.

@Xingcai Wu typically @Bob Floss II is right but the one way I see it fall apart is when the tenant doesn’t do what they need to do in the admin side to get the assistance grant.  

You only need a license to originate paper if the loan falls under the TILA RESPA guidelines.

Give the construction details to your agent and they can advise if the amount of work falls under the standard policy or if they will need to endorse additional coverage onto it.