Not sure on the selection wheel - mine feels as precise as it needs to be. I think it is meant to be a little more forgiving so that you don’t do huge jumps when you turn it quickly.
As far as the up/down arrows.
That behavior is correct.
It is basically up or down on the screen not in value. (if that makes sense) You are moving the active field so if you wanted the active field above your current field you’d push it up.