I agree and disagree with those points.
The most evil aren't civilised so they don't deserve to live in a civilised society so individuals who are of the ilk of the likes of Jimmy Saville, Donald Nielson, the Harpe brothers, Jeffrey Dahmer etc ought to be put down. Innocent people die every day so why should we care about scum like this?
As for drug traffickers, first time offenders shouldn't face the death penalty because of the reasons you've given in this thread.