If you give them an inch, they may take advantage of the situation, regardless of the existing relationship.

Until you get into the property and take a look at every square inch of the place, you're really just playing a guessing game.

In the worst case I've seen, we took up the baseboards and cut the lower ~1 inch of drywall (with drywall saw), cleaned and Kilzed the base boards front and back, and reinstalled.

It is better to go a mile deep and an inch wide, rather than a mile wide and an inch deep... in other words, focus on one or two niches and get really good at them.

@Robert Niosi  two things one foundation and two the house was just built out of plumb to begin with.One of the builders here in Oregon was in a subdivision I was building in and they built a home that was 3 inchs off of plumb if you dropped a ball at one end it would roll out the front door... cabinets and doors all looked funky

Also, by attaching new treads on top of the old ones, I will be reducing the top step height by about 1 inch.

Usually I'll install 4 or 5, 4 inch lights (3000-3500 lumens) in a kitchen so if one goes bad it's not an emergency.

The problem is, at this point of time the lead is so mixed in with dirt and debris, proper remediation requires removing several inches of depth of the top soil, and replacing it with "clean" topsoil.

You will have e to clean every inch of the house.

Not every inch of the area is crime free or thriving.