What roles do easements, drain lines, utilities and soil samples play in determining the value?

If the soil near the foundation is not getting enough water and dries out, it may cause issues with the foundation settling. 

My background is in ecological design, which you can find out more about in my profile, but in short it means I design and help create abundant edible landscapes that not only grow healthy food, but also enhance the ecology by purifying water, providing habitat for wildlife, and actually sequestering Carbon dioxide from the atmosphere in soil and plants.I have much gratitude to the creators of this space for creating something that is truly inspiring and brings people together.  

I assume the patio and jacuzzi were somehow permitted within a utility easement.Are the utilities underground underneath the patio/jacuzzi?  

If it's a slab, it depends on the cause of the problems and the underlying soil. 

It helped that the walls had an oil-based paint underneath.

I will go to the building department. regarding the property I am looking at what would my bank do prior to closing a loan secured by the property to make sure there was no contamination in the soil?

Unless its a corner lot, that means raising the house for parking underneath.  

I've disturbed the soil frequently.

The house was built in 1980 and the soil in the area is bentonite.