Yes of course find a good attorney to structure the partnership, but:1) what kind of attorney works on this kind of arrangement?

That's the most common setup.If this is not an urban environment and you have water coming in from a well, then your setup doesn't include the same arrangement.

Exit Strategy: What are your options if you want to get out of this arrangement in the future?

A google search of NC Landlord Tenant Laws Chapter 42 should get you what you need. https://www.ncleg.gov/Laws/Gen...Also, if the tenants are paying monthly then it sounds like they are on a month to month type of arrangement (since there is not a lease) which would mean a 30 day notice would need to be given.

He can then gift his share of the property to you or you could have a buyout arrangement over time. 

PM me Mike and I'd be happy to share my agreement docs and arrangement on a recent deal.

The nature of the reasonableness of the notice seems to be to give you time to pick up theplace, secure pets, arrange to be there, or otherwise make ready for the visit.

I originally chose this arrangement as my dog has separation anxiety.

Maybe, he can co-sign for you or some other arrangement. 

With the size of the main property and land it might be possible to arrange for a seasonal rental or subdividing the property to sell off or build another residence.