And the buyer is only half the situation.

Perform a simultaneous exchange where the sale and purchase are both scheduled and occur within a day or two of each other.The easiest way for foreign nationals to get away from the FIRPTA requirements is to purchase and hold property in domestic LLCs. 

The ADU now covers over half the mortgage + additional monthly income per horse the tenant desires to keep on site.

Quote from @Trent Reeve:  but its hard to say its from that, or that guests are getting smarter and looking for direct billing sites to save money on Airbnb and VRBO feesGlass half full! 

New to real estate investing so any help/recommendations means more than you know :) Does anyone know what would be the easiest or most efficient way to go about getting a new quadplex built in the Greater Atlanta/surrounding area?

House hacking your primary home and repeating the process every year or two is the easiest and safest way to build long term wealth through time. 

On the other hand, at the auction Wayne County held back in the Spring, about half the auction was the  listings for Sterling Township inside Pocono Springs.

Or should we take the month to month rent and probably the market won't be that bad this second half of the year?

So we can take the original LLC that is 50/50 owned by 2 people and move half of the properties over to a new LLC where one partner now owns 100% and then the other partner would have the other half of the properties and have 100% ownership of that one and we pay no taxes?

The easiest way is to bring on a partner who has a lof of capital they are looking to deploy, but I always encourage having sufficient reserves.