If so, it needs to be separate and properly ventilated.  

-Not sure of the overall 'market' for duplex renters vs SFH.. this area is a suburban, working class neighborhood not within walking distance to a proper downtown.. thus do I need to be concerned that I won't find qualified renters (probably hard for someone not knowledgeable of the area to answer, but nonetheless is a concern).- I'm struggling to accurately assess the ARV, as there are not many comps available for assessment.

A properly-formed, properly-operated LLC is like a firewall for liability: everything inside might burn to the ground, but the fire won't get to things outside the LLC.

Did they give you proper notice to vacate? 

No issues with proper disclosure and appropriate ethical boundaries.

Would rather top notch CPA who understands real estate laws so you are setup properly for the long run.Lender, depends here. 

Like @Jay Hinrichs mentioned above, it's not an easy job.

Some people get so laser focused in one direction, its easy to let life pass you by. 

Going up through walls is easy, often just 2 small holes in the wall, one to drill the plate and and one for the cat, the cross piece between studs usually halfway up a wall. fishing in the direction of the joists is easy, going across them can be done with small holes spanning the joist, notching it for the cable, and then put a steel plate over it.Given that your problem unit is ground floor, it's likely you can fish up from the basement very easily for outlets using "old work" steel boxes, plastic boxes don't work with plaster on lath, it's too thick.

If anyone can shed light on what he meant or how to structure these properly, I'd greatly appreciate it.