Indeed.
4. Giving the state the authority to kill it's own citizens opens up it's own set of moral & ethical hazards & is far to authoritarian for my liking.
Agreed, and I dislike the notion of this.
However, the 'previous' situation before the existence of such as thing as a 'state' was that one of the affected family members would seek retribution, and so you end up in a tribal-style blood feud situation where random killings keep going on year after year.....
And I was disappointed that it only took him ~40 minutes to die. He's had 15 years of life longer than his victim, so I don't feel even slightly sorry for him. Maybe that's a barbaric view. Oh well.