1)
Why did Achitofel say that he will strike David, and not Avshalom?
1.
Malbim: It is improper for a son to kill his father. I am Go'el ha'Dam; David killed 1 Uriyah (the husband of my granddaughter)!
1
David commanded Yo'av to cause his death. Is this like Shamai, who holds that Yesh Shali'ach li'Devar Aveirah (Kidushin 43a), like the opinion that Shamai obligates bi'Ydei Adam? (PF)