I understand I wouldn't get the benefit of tax deductions, but what else am I missing that makes this a good deal? 

Tons of bureaucracy and headaches dealing zoning, DCRA and many other obstacles.

Nothing will piss off the inspector faster than missing an inspection.My last piece of advice, in an effort to not make this a book length post, deals with the money.

If you are using it to buy a turnkey property which needs to produce cash flow to be considered a viable deal how does buying turnkey(Little to no cash flow) combined with HML(High interest only debt) make alot of sense financially? 

Cash invested: $18,000 Sale price: $32,000 '69 trailer fix and flipNew flooring in kitchenAdded ACNew windowsAdded GarageNew interior panelsBathroom reno What made you interested in investing in this type of deal?

Several ways to skin that cat  ;)    With the DSCR lender, you could close directly in your LLC and it would not report to credit.

No where was it stated that this deal was contingent on cross collateralization. 

Hopefully this gives you some direction.

For example, in Dec I had one property 100% direct/VRBO which historically 40% Airbnb.

Not a bad idea but if the deal goes bad just remember you are taking money from your primary residence.