The school’s accreditation remains in place while the review processes are continuing.”In other words, if they don't clean up their act, the place where he got his law degree could lose it's accreditation.  

Once you do that the store owner may clean up the act to keep his license.

There is some opportunity for "baskets" of land that really aren't positioned for a specific buyer (think of one parcel that is half hunting timber and half tillable, with maybe a wetland issue or two or some work to clean up a square piece for farming) where you could go in, tidy things up and do some savvy dividing. 

If anyone is masochistic enough to be looking for an exercise or case study in this, look up the Federal Realty Investment Trust project at Assembly Square in Somerville MA:  a former Ford plant turned barren wasteland with (over time) multiple environmental matters on site to clean up.   

Easy for me to install, very durable and clean up very easily. 

I helped clean up billions of dollars in failed bank assets and the large majority of bank failures were due to poor underwriting.

I'm not saying your are legally liable for anything, but I'm sure you don't want to have to be doing some dead body cleanup in your personal residence.

They estimated and quoted full restoration of the fire damage which included soot cleanup, odor removal, clean air filtration (out of fear there may be something harmful in the air from the items that burned), and floor replacement.

3) If, upon removing the fence and placing the stakes and string on the actual line, we were to clean up and remove "their" pile of yard debris, would this legally constitute "use" of the property by us and thereby negate any claim they could make to "exclusive" use of the property over the past 14.89 years?

If the only motivatation is dependent on a feeling of guilt, all children would put away their toys and clean their rooms and all trashy neighbors would clean up their yards.