Now you are just making this up. Empathy and guilt may serve as motivators, but they are not the only motives a person has to learn, otherwise we'd all be door knobs.
No, not the only ones...but important ones.
Then, if you talk about predictability, you might as well throw your argument away, since I'd wager empathy and guilt would actually lower the ability to predict that person's actions. Also, he'll show restraint because that's in he's best interests. He's supposedly without empathy and guilty, he's not stupid.
You're assuming he'll do what's best for him instead what's best for "the world"..or humanity. If he decides that it's best for humanity to remove you and your family...or some group or another from the gene pool.....
Lack of guilt/remorse, a strong belief that the end justifies ANY means and that when someone does something for the greater good, that action is always good - and you're wondering how I'm NOT worried?
But again, you are trying to force them to do something we'd have no obligation to do so too.
Society frequently forces pople to do stuff. Nothing new under the sun.
As long as it doesn't hurt anyone I can live with it.
Seeing a councelor a few times - OH! What terrible torture!

Considering we don't know exactly how the brain works, it's difficult to decide who is "broken." We know a lot, but we don't know enough to say who is going to be dangerous most of the time. The vast majority of the mentally ill are dangerous only to themselves.
Oh, but lacking some pretty basic emotional response does mean the brain doesn't work right.
I don't have to be a mechanic to know that a car is broken if it's breaks don't work.
Now, let me get back to this statement:
"Anything is justifiable, morally and personally, if you win the battle/war/confrontation said action is committed in."So let's say I kidnap you, turn you into personal slave, do all kinds of unspeakable things to you and then kill you. Now, no one discovers your body. That means I got away with it. That would also mean that everything I did to you is justifiable, because I won.
Heck I can think of some reason to kill you probably - it doesn't have to be the truth, nor does it have to be good. It can range from "removing idiots from the gene pool", "you've killed JFK" to "you're an evil alien ghost that wants to destroy mankind".
Does that make my action personally and moraly justifiable?