SOPs are not a one day job research. Nobody came up one day and said " this is how to do it " We learn every day and it is a never ending process.
I try fairly hard to adhere to SOPs in my daily routine, I find it produces less conflict and I don't have to alter my style relative to the "coolness" of wichever captain I'm flying with.
Principled Adherence should be weighed differently than SOP itself. The former reflects flight discipline and a systematic way of adressing threats. The latter is negotiable, transient, and widely varied. Your airline and mine operate the Airbus family. Yet 8 items on your list either contradict our SOP or are not addressed at all. Yet in our fleets several million hours we haven't bent anything. So there is more than one (safe!) way to skin a cat.
SOP is valuable, but not sacrosanct.