The only thing that worries me about young players is being able to make it through an entire NFL Season + playoffs without getting injured and knowing their assignments.
It's tough to get used to the grind of playing against grown men...Once you conquer that battle, then players tend to settle down and play the game.
That's where Kiser is at right now...He's settling in to the speed of the game and he's not thinking, he's reacting. He's playing football without worrying if he's making an assignment mistake.