This has proven ineffective as most of these properties' income can barely sustain themselves [even with a "larger" (20%-30%) amount of equity down] and the ones that do have worse returns and higher risk than if you were to put money into a CD, for example. 

Hello @Andrew T.Didn't recognize you there. :) 

Also I find real and proven returns in Pontiac which is 10 mintues from my house and my manager goes there.  

As an example; even if actual vacancy rate can be proven to be zero for the last 5 years, the bank is still going to assume a vacancy rate more typical of the area.

They are usually NG and propane compatible and I'm speculating that a lot of the maintenance/longevity issues can be sorted out by doing a proper installation with water filters to cut down on heat exchanger scaling, which seems to be on of the biggest complaints.So I'm betting on the newer, more efficient technology but I also see the draw towards sticking proven oil boilers.

Be careful, the ADA only recognizes dogs for service animals, but residential rentals fall under Fair Housing that accepts any animal(s) as ESA's, and violations of the Fair Housing Act are very expensive. 

If so then you will not receive your funds until then so your accountant could treat the initial sale as an installment sale with no receipts and have all of the receipts come in 2019 which means that your gain won't be recognized until 2019 so you won't pay tax until April of 2020.  

So now if they go to a bank or some other investor it would seem to me that they could get 10% down 5% down or something similar, because they have a proven record over the last 10 years on hundreds of deals, of 0 defaults?

It was a really good investment at the time, and has proven to be the best one I've made. 

If you have anymore suggestions on how to recognize and find good deals, by all means go for it.