I only had a firefish for like a week. It died after I added PH buffer to my tank along with my red starfish I got at the same time. It was a bad week and I will never use that stuff per the directions again!
Mine hasn't picked at anything but the rocks so far. I do have some zoas but I thing they are freakin boring anyway so I dont even care if she does. LOL
She does love seaweed and veggies so I be sure to keep her fat and happy. She is so active and curious I love her already!