humidity trays are minimally useful if you ask me, the greatest utility being catching the run-off. might add 4-6% to the humidity in the immediate area. paphs want to be evenly moist, never drying out fully. they should NOT however remain constantly wet like phrags, or else the roots may rot in short order. light depends a great deal on parentage. your standard paph will exist under low light but will rarely bloom. most paphs prefer bright shade, and a few would be happy alongside cattleyas.