If you are moving/opening walls that would definitely require stamped plans. 

There is more to enclosing square footage than putting up a wall, sheetrock and siding.

How do the inside walls and door jambs look?

That's right, nothing says complete waste of money more than a concrete floor bedroom and standalone makeshift closet.

This leak was likely happening before, going unnoticed, because there is damage to the kitchen wall and connecting bathroom.

The writings on the wall.

So far as I am told the tenant broke the soap dish tray off of the tiled shower wall and notified the seller in June 2020.

Example – someone tried to steal the heat pump – cost of repair and recharge ($480), cost of AC cage ($380) etc.Work done:New roofNew LVP flooring throughoutPaint entire interiorNew bathroom New doors inside/outsideKitchen appliances and cabinetsTree trimming/cuttingGeneral yardworkDrywall hanging/wall repairDid you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Get the clock started, don't waste another moment.  

The walls will need to be painted with killz to get rid of the smell.