Well... You don't want full knee extension. Kind of close, but not full.
Regarding shin angle.... maybe close to vertical, but I don't find that a helpful marker for 2 reasons. One, if it's a little off vertical, are you really going to be able to tell? Two, I'm not sure if the shins should be perfectly vertical at that point - probably a little forward of vertical actually.
The scoop is the forward movement of the knees under the bar during the double knee bend. It would occur at that "jump" moment, but it's not really the same thing.