I don't see where you got the idea that members of the order of pheonix don't kill when necessary. I mean sure they don't use the killing curse but there are plenty of curses that can be life-threatening or situations that lead to killing. Case in point: i remember in the beginning of book 7 when Lupin got stern with Harry for not knocking the death eaters off their broom (leading to their deaths) and only using the expelliarmus. Sorry this was bothering me for a while
Honestly the only thing I don’t like is the idea that Harry isn’t powerful wizard for his age. In the books he’s pretty stongs. Obviously he’s not super powerful but I think he’d have his third maturation before or in his sixties maybe even in his seventies.
Mr_Shang