Regrade the whole yard or just the patio?

I recently bought a narrow rowhouse, built in the late 1800s. I'm at the end of the row, so share a wall on the west side. I also abut against the detached home on the east side. My kitchen is a few feet narrower than the rest of my house on the east side, so I have access to 20 or so feet of my east wall (the length of the kitchen). The rest abuts the neighbor. My basement is brick except for the portion at the back of the house, under the kitchen, which is poured concrete. Aggregate used for the concrete was river rock, and there is spalling and efflorescence (this also appears on the shared wall, not just the wall directly exposed to the earth). My home inspector thought the walls were sufficiently thick that I could get away with patching. On the brick part of the basement, there is efflorescence and occasional deterioration of bricks (again, this can also be found on the shared wall, not exposed to earth). The dehumidifier runs non-stop. My downspouts extend 8 feet away from the house. When one came loose at a joint against the house, I got water in the basement during a rain. I have wood-soil contact that I'd like to break (I live in a termite area - although if my neighbors haven't broken their wood-soil contact, I may be wasting my time). So basically, I would have the patio area dug down 6 or so inches, ensuring a slope away from the house in the process. My questions are: Do I need to dig the whole yard down, vs creating a sunken patio?. Would it be worthwhile, at the same time, to have the contractor dig right down and replace the weeping tile at the back of the house and waterproof the foundation walls (keeping in mind I'm at the end of a rowhouse, but I'm also abutting the detached house next door, so can't access the exterior foundation wall on that side)?