Shear is wall, tension is ceiling.Yes its these using 2 one on each side to hold the rail, these ratings are for side walls not ceiling
Yes, if they are equallly distributed then the force is equally divided.Actually it says 1/2 inch drywall tension rating is 74lbs, my light is 14 pounds and assuming tension is downward force…does 14 pounds hanging 2 anchors split the weight by 2?