don't add any iodine to the tank. everything you need to keep fish, inverts, and corals is in your salt mix.
it's hit or miss trying different alleged hair algae eaters. one that might work for a friend, might not work for you.
i don't think you are overstocked, but the maroon and the coral beauty can be territorial. sometimes it's better to add them last. they may not accept a new addition with open....fins.
since you don't keep photosynthetic creatures in the tank you have no need for a lighting schedule. i would turn the lights on minimally, and keep doing water changes to remove nutrients while i kept the feeding very light. you will starve the hair algae out in no time.