It's netflix im suprised they are not in their teens. Netflix just casts the same people in every show based solely on looks and age. Acting ability never comes into it
That's not coke at a guess i would say he may be withdrawing or coming down from something.
As for Gyllenhall he is well known for being a huge jerk in real life and on set so i doubt he has much of a choice in any roles he gets these days.