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
Answer:
decided immediately
Explanation:
"impulsive" in this context would mean deciding without thinking about it first
Hard or difficult would be good synonyms for arduous.
Hope that helps.