No. That's like beating a child do well in school, and then saying the abuse is the way to get results. You have to ask yourself "at what cost" if you are going with that logic. And even still, one's idea of justice might be different from another's, so no one can ever really say the end justifies the mean.
Rarely, but sometimes. Unfortunately it's usually said to justify unjustified means and assuage feelings of guilt.
Not usually. But maybe if no one is hurt.
No, I do however think the means justify the end.
Excellent ? and 1 that continues to plague humanity,, as to how to best answer/reply. Most strictly speaking,, NO the ends never justify the means. But human knowledge keeps increasing ( thank god),, as in,, if we knew or if the Supreme Court knew in 1973 what we now know to be absolute scientific/medical fact,, that life begins at conception --- all you're gonna be,, is 'fixed' right then,, there is a very good chance that Roe vs Wade,,, wouldn't be law of the land. In that case the 'ends', women's liberation,, as it were,,, DID justify the 'means',,, abortion sad to say did free millions and millions of American girls/women,, to be,,, fill in the blank as you feel most appropriate.