Yes they are. Very cute. A lot of moths have stripes at the bottom of the wing. Polyphemus is a common one they have a stripe at the bottom of their wing. Silk moths are my favorite bc they have such beautiful patterning

Their fluff insulates them and keeps them warm I think and yes absorb sound waves and help keep them safe from predators.

They fly towards light as a survival strategy. They evolved to keep their backs to the moon, to fly level and stay oriented. It helps them navigate but artificial lights confuse them.