Head/lateral line disease is often due to a poor water quality and a nutrient deficiency. The poor fish must have been stressed out in an LFS due to shipping and subsequent water quality issue. It may not have been eating the right food, either. Foxface and Rabbit fish will eat any food if you'd let them, but they really need some greens in their diet.
Good job, Tim. I am glad that your fish and snails are eating your problem away. Keep an eye on your water quality. Once they are done with your algae, you can start feeding your fish. If you really want to feed your anemone and maroon clownfish, try to offer food to your clownfish with a turkey baster so that other fish cannot get to it. Good luck.
Tomoko