My #1 goal is still to find potential off-market deals, but my #2 goal is to secure listings.Would it be viable to advertise both cash w/ fast close and listing services on the same mailer? 

He collects social security and has a part time job.

Mortgage rates are driven by the capital market and basically follow the bond market, specifically 10 year US treasury with a premium, historically about 1,7%.Yesterday the 10yT fell to 3.9% and I have seen 5.99% 30y fixed rates with a local bank in here Milwaukee (that is still an inflated 2% premium), so 5.7% would be historically normal based on a 1.7% premium, even without the 10YT going any lower.Here is why.If the 10yT offers lower returns, more investors want to buy mortgage-backed securities instead to get higher returns (about 1.7% higher), as a consequence lowering the returns on those as well.

Still better than renting and wasting 4-5k per month on a place that isn't even as nice or big as the home I was able to secure.

I have looked through the Offering Circular and it states (contradictory to what they state on the website) that the notes "are not secured by any collateral and are not guaranteed...[]". 

By leveraging our experience and Seth's insights, we secured the property at a favorable price that allowed room for renovation and a profitable resale.

Anyone with a LT lease in place who has collected either two months rent or security and first months won't get tagged for vacancy. 

By leveraging our combined experience and Seth's market insights, we were able to secure the deal at a price that allowed room for renovations and a profitable resale, ensuring a successful investment.

I might consider them if I had no other candidates , but only with 2 months security deposit in addition to the rent. 

Negotiations were swift and efficient, allowing us to secure the home for $185,000.