I know there are hundreds (thousands probably) of lenders out there that offer a DSCR product.

We have a 30Y Fixed DSCR product that would likely fit your needs. 

For walls in common areas like halls and stairs, there are rigid products that can absorb some sound.

I wonder why they don't make roofline sprinklers or some other product like that. 

If the latter, people have tightened there wallets and certain areas are seeing a decline.

When you go to a Bank or Credit Union, they can only offer you what products that bank or credit union offer. 

Freddie has a reno loan product that can be used for investment properties; this is only for first position, though.For the Heloc - it goes back to whether your mom wants to continue carrying the loan for income, and if so, how will you pay off the heloc once the rehab is complete?

And I think a lot of companies will realize that productivity is generally higher in cooler climates.

Small shop brokers that have access to multiple programs so that they aren't beholden to one or just a few loan programs will typically get the most competitive product for the borrower. 

The analysis also reports that new multifamily development will “remain near the average recorded over the past five years”.Integra Realty Resources’ 2017 Commercial Real Estate Trends Report ranks Pittsburgh #2 on its Top Markets by Multifamily Transaction Volume Based on YoY Change.Pittsburgh’s rental vacancy rate has declined by 25% over the last five years.Pittsburgh is booming with developments (see reference #6), “there is no better place to be a developer right now than in Pittsburgh.