For the aphids removal in my schefflera, I have used a mixtuer of water, rubbing alcohol, dish detergent, spraying them liberally. I do it early in the day so it will not burn the leaves and allow dry off.
Leaf curling on your 2nd photo, could be over watering/over fertilizing. Remind him to check the soil before he attempts watering. Or try to see the position of the plant if it is too near a very hot window/ very hot sun,maybe re-orient plant location if possible.
