Make a list on a yellow pad of every picky thing that needs completion: drywall, type of texture, electrical outlets, molding, all the interior trim, I assume you have pre-fab cabinets sitting in a garage if not - you need to, doorways and door hanging, all the walkways and outside hardscape are done?

He just finished demo-ing the old building and told me that our property encroaches on his (according to his survey) by 4 inches- the 4 inches are all sidewalk but would make the walkway on the side of our building narrow if taken away.

I would look at the walkway around the pool near the building corner. 

The walkway has zero slope.

If they really are eroding then I would walk way form that deal because there probably is bigger issues which caused the erosion to start with. 

Also make sure you're having common walkways and stairs cleared of snow, typically you have to pay extra for this.

I do not want buyer to walkway after the deal in pending a month.

There is a 3x3 metal hatch door in the walkway leading to the front entrance to my bldg.

Can you put a parking space or two on the other side of the front walkway?