As for #12, the shape of the head seems wrong and he's way too stern to accord with the images of Epicurus that I'm used to seeing.
I agree that this is more stern than most, but I see this as consistent with his dominant presentation in the remaining busts. I would probably call it more "piercing" or "serious" than stern, but I think that's likely the way he was perceived -- as very SERIOUSLY pursing his philosophy.
For example this one, which is not one of the small ones from herculaneum but which makes him also look serious:
And look at the focused / concerned eyebrows here:
As for the deviant version - let me get this out of the way - I see the deviant version as THIS one which many commentators today like to use because the damage to the eyes and angle of head can be lighted in a way that makes him look like a stupified pot-head 
This is the one I see as - in its present form - out of character. If it were an attempt to make him smiling, I would say it's acceptable, but even before the eyebrow was damaged it appears to me to be more of a "blank" expression, which again would not be a good look for someone as acute as Epicurus.
