So your answer would be paternal since it means father
A king inherited the wisdom from his 4 bears
Macbeth has been adapted so many times for the same reason why all Shakespeare's plays have been adapted so many times. It is because they are not bound to a single point in time and by changing temporal details it can be applicable to any society at any time. The theme that is "power corrupts" has been ever present and this is why it keeps getting adapted.
a string of shells as stated "When a new lord joins the council, he must offer a pledge of four strings of shells."