What is your pricing structure?

How the deal is structured does not matter. 

This offer is basically for the lot as the house needs everything from top to bottom but appears to be structurally intact......just old and neglected. 

Meanwhile you can rent the home and benefit from the deal structure while sharing their percentage of proceeds with them or the estate.  

During the feasibility period I'm planning on conducting the usual due-diligence with a thorough inspection of all the property's systems and structures (utility services, roof, HVAC, maintenance history, lot survey, tenant interviews) along with a Phase 1 ESA. 

How can you structure this so that a single entity or person manages the responsibility, while the other investors who help pay for the down payment are on the outside?

I should have set more of a timeline and payment structure up front, but I will not be working with him again so not the end of the world.

The house deeded in your own name means a normal conventional refi, but it is complicated by the structure you are using to run the STR, with the business run by the LLC. 

@John AcklenDennis Stemler is the structural engineer I use.

Each State has different rules re: what happens to your ownership structure if you tax merge parcels.