Awesome additions! That urchin has me cracking up! Toooo funny! To me this is what separates a reef tank or makes it special, there is sooooo much going on!
My bro in law just upgraded from a smaller reef to a 72 bow like my discus tank. I think seeing his tank made me add the tank mates to my discus that I did, just to see other species and life doing what they do.
Watching a reef tank is like sitting in the middle of NYC, there are a million things to look at!