I'm looking for a cheaper and more sustainable option than renting and figured house hacking (buying a duplex) while rehabbing, then renting the other unit, and refinancing would be my best bet.  

However, if the $31k lien makes the house “under water” he could claim the inability to bring additional cash to close, going back to the “ability to deliver clear title” clause.I’m just going off Our standard realtor contracts.

in addition to the paid national searches most of us do.

Your best bet would be a community bank. 

My goal is to build up enough cash flow with adding additional rentals(15-20 rentals paid off) to one day being able to afford a vacation rental and renting that out until I’m at retirement age.

In addition you need to be able to provide the new tenant the keys so you have to somehow keep track of them because I doubt that they want to break into the house every time they want to enter.  

Probably not, you'd probably only consider this because you had bad credit or low income or something that prevents you from living in a safer place.I bet the turnkey provider has rents too high for the area as well...Can you make money on this type of asset...sure but not by paying 70k for it.

Additionally the subject property is a split foyer while all comps are bungalows.

We ripped off the "indoor jacuzzi room" and breakfast nook because they were horribly done additions that were already falling off the house.

I’m an investor in Atlanta Georgia  and I’m used to getting rehab quotes from GC’s that are between $35/sqft (not too much walls need to be moved or roof or anything) to $65/sqft (everything needs to be done) to $85-$100/sqft (new construction or additions).I read about and have ran into other investors who say they can do a full rehab project for about $15/sqft !!!!