If the vapor is coming from the soil, wouldn't the proper way to remedy the situation involve actual soil removal/clean up?

It was on a crawl space and we moved all of the mechanicals from the kitchen dining room area to underneath the house by digging down about 4' and building a block foundation area just inside the stone foundation and pouring a new floor and adding a sump pump.

It was on a crawl space and we moved all of the mechanicals to underneath the house by digging down about 4' and adding a sump pump.

In CA, your inspection clause allows the buyer to bring in inspectors to determine the condition of various portions of the house.Home inspector inspects the general well-being of the propertyGeo engineer inspects the soil of the propertyetc.In CA, buyers have 17 days to get all inspections done and sign off on the inspection clause. 

Kitchen was lengthened to about 30' and cabinetry and appliances were rearranged and upgraded. 24X16 deck added to rear of house and a slightly larger patio was poored underneath.

If it is me I'm keeping the tree and putting down pavers with proper drainage underneath, the only exception would be if you have a pet and/ or allow pets in the unit.

I thought part of the floor was dirt; turns out there is concrete underneath after all.

The bent beams have lost most of their strength to resist the soil and water loads against the foundation. 

I hear everyone saying to not file for bankruptcy but I honestly don’t know how else I’m going to get out from underneath a $90,000 hole.

Though you can pull from the IRA over those three years in smaller amounts and strategically stay underneath the threshold you prefer.