I have rototilled, regraded, and planted new grass. I sealed an
asphalt walk to the foundation with driveway patch. I extended
all the downspouts. This has made a huge difference and stopped
water from coming in even during heavy rain. My dehumidifier has
gone from removing 58 pints a day to about 5

Yup. It's often astonishing how much improvement is possible from such
steps - sometimes a single "small" defect in guttering or downspouts
can deliver a surprising amount of water to a basement or crawl space.

Here a writeup (with pictures) of a classic example:

http://paragoninspects.com/visual-gu...basements.html

Michael Thomas
Paragon Property Services Inc., Chicago IL
http://www.paragoninspects.com