Only 1 problem with "No out of combat opening attacks" how do you do that in a game that has you use magic to clear dangerous ground effects or blow up doors and crates etc.?
It would have to be a special flag just for enemies then? What if those enemies stand near a barrel, and you target that? Seems like a solution, but in practice first-strike is in the game because of certain design choices. I doubt it could be easily removed without breaking the game. And to begin with, some battles would have to be re-designed entirely. Right now some situations are clearly made with first-strike and certain move order in mind. ANY encounter with bomb carriers for example. Imagine the trap with the chest and the 12 explosion guys, with random initiative
You'd be dead unless you are lucky.
Not saying that makes your conclusions wrong, I am saying the game was not made for these changes. And there are plenty of situations where changes have secondary effects. To begin with the entire stealth and even the TUTORIAL would no longer work.
Reminds of the saying "There are simple solutions to all problems, and they are all wrong"