I was hoping to make this into some kind of sticky, but here you go :

Which skills matter more than others is still to be seen, but here are the basics:

All positions to some extent: Vision, Positioning & Stamina

Offense:

QB: Passing, Vision, positioning, Intelligence, Footwork, Agility, Stamina, Strength with maybe carrying and Speed

WR: Speed, Catching, Agility, Vision, Positioning, Stamina, Strength, Carrying, Footwork, with maybe blocking and intelligence

RB: Carrying, Speed, Vision, Agility, Strength, Positioning, Footwork, Stamina, with maybe blocking, catching, and intelligence.

FB: Blocking, Strength, Speed, Positioning, Vision, Footwork, Stamina, Agility, Carrying, with maybe some catching and intelligence.

TE: Blocking, Catching, Strength, Speed, Agility, Positioning, Vision, Stamina, Footwork, with maybe some carrying and intelligence.

OL: Blocking, Strength, Positioning, Stamina, Vision, Footwork, Agility, Speed.

Defense:

FS: Speed, Tackling, Vision, Positioning, Agility, Strength, Catching, Stamina, with maybe some footwork and intelligence.

SS: Speed, Tackling, Strength, Vision, Positioning, Agilty, Catching, Stamina, Blocking with maybe some footwork and intelligence.

CB: Speed, Agility, Catching, Positioning, Vision, Tackling, Strength, Stamina, Footwork, and maybe intelligence.

LB: Tackling, Strength, Speed, Vision, Blocking, Positioning, Agility, Stamina, Catching, Footwork, and maybe intelligence.

DT/NT: Tackling, Blocking, Strength, Stamina, Positioning, Vision, Agility, Speed, Footwork, and maybe intelligence

DE: Tackling, Speed, Agility, Blocking, Strength, Positioning, Vision, Stamina, Footwork, and maybe some intelligence.

Special teams:

K/P: Kicking, Punting, Strength, Positioning, Vision, Footwork, and maybe stamina and agility