Found a math error on page 39 of the PDF (under excavations). You state that a character with proper tools can excavate five cubic feet of earth per hour. I think you may have meant 125 cubic feet (length x width x depth is the correct formula for volume). Five cubic feet is a hole five feet long x one foot wide x one foot deep. 125 cubic feet would be a hole five feet long x five feet wide x five feet deep.
That brings up an interesting tidbit. 125 cubic feet is about the size of a rough grave (six feet x three feet x six feet), so burying the dead in a respectable grave (or hiding bodies) wouldn't take as much time as you'd think for a decently-sized adventuring party.