I don't think I would consider blind obedience, the most evil thing a person could do but it definitely is the most amoral.
You know, I fail to see a functional difference.
I may be wrong but to my understanding evil implies malicious intent, where as amorality dose not.
one functional difference is that in most legal systems, intent is factorized into judgement and sentencing.
On a side note, often if remorse is shown by the convicted a lighter sentence is given.
Mens Rea is generally divided into four levels:
Intentional - I did the thing intending for the outcome to happen
Knowing - I did the thing knowing what the outcome would be, though that outcome was secondary to whatever I was intending.
Recklessness - I did the thing knowing there was a substantial risk that the outcome would happen, but I didn't care.
Negligence - I didn't know about the risk, but as a reasonable person I should have.
One thing to note is that "I didn't know, and there's no reason to expect that a reasonable person should have known," doesn't even register on that (though in many places there's a fifth quasi-level called strict-liability to catch that situation, a.k.a. "you made the mess, you at least have to clean it up").
Point is, intent and awareness
are both factors. Amorality can be a result of apathy. But it can also be a result of ignorance. May be useful (at least for philosophical wankery purposes) to have a third word beside amorality and immorality to catch situations where there's no question of morality because...well...there were no questions.