"lift out, hold, deposit on nearby seats, or maneuver over the seatbacks to the next row, objects the size and weight of over-wing exit doors;
remove obstructions similar to size and weight of over-wing exit doors, all while maintaining balance;"

i cannot perform this task. i doubt if more than 10 or20% of the people on the plane can do this. very few female FA's could do this. a 50lb door with some 2' x 4-5' dimension.

this task requires a strong person, not your average desk jockey.