Any advice for finding / approaching owners for off market deals? 

As I approach my 20th year as a real estate broker in Texas and my 30th year as a small business owner, I've decided to think outside the box and use what I have to get what I want.  

Hot water is usually separated it is just the cold water that is often not.For a very large building a flat fee is the move because the back billing and tracking of who paid for what would be hectic, but for a small MF like a duplex it is very easy.I split the bill by the fractional amount of people who live in the unit.In other words, the amount of people that live in the unit divided by the total amount of people living in the builidng.So if there are 3 people upstairs and 2 people downstairs.the upstairs pays 3/5 of the bill, and downstairs pays 2/5.No need to separate anything, you know the tenants will cover 100% of the bill and this approach is fair. 

You can use the same market approach.  6.  

This approach focuses on finding deals and connecting buyers with sellers, helping you learn the market and hone your negotiation skills.

Changes in Buyer Behavior: If buyers are directly responsible for their agent’s commission, it could alter the way they approach negotiations.

On a final note, please verify that there is a demand for this unique investment approach in your market.

My broker has been approached by them as well, and it sounds like the exact same thing. 

Market Suitability: Are there certain parts of Cincinnati or property types that might be more challenging for a BRRRR approach, especially for someone with limited time?

You'll have a tough time finding decent cash flow in Raleigh given your numbers if your approach is buying turn-key on market properties.