Good job on getting advice and actually listening to it about the mandarin. That definitely would not have worked out. As far as your other fish, as you may have noticed by now damsels are very tough and scrappy. If you are keeping the 2 damsels in your tank I don't think you'd be able to add anything else. If you are taking them out, the cinnamon clown would be fine for a while. But they can get fairly large. Adding 2 domino damsels would also prevent you from adding much else. They too are scrappy and territorial. If I were you I would go with just the cinnamon, or a pair of tank raised percula or ocellaris clowns. The cleaner shrimp and a couple peppermints would be fine. Since it is a small tank, you could also go with some sexy shrimp, some perimenicles (sp?) anemone shrimp, or some other cool little shrimp that you wouldnt normally see in a large tank. Not sure if these little shrimp would survive with damsels though. Just some suggestions. Great start and good luck.