no its not nute burn i dont use nutes.. the yellowing is when the plant died and i had to rejuvinate it that oart of the leaf died... its not dust because its in the leaf not of it its a bit at the tips too if u look real close..
mites for sure...most insecticides don't kill them. make sure whatever you use, that it lists spider mites on the label or its a waste of money and effort.
walmart has a product called fungicide 3- its only like 7 dollars and includes fungicide, insecticide, and miticide... seemed to have worked ok on mine