Those things with the tentacles on your rocks appear to be aipstasia, which is a nuisance anemone. Most people kill them with Joe's Juice as soon as they see them so that they do not spread all over the rocks (which they are notorious for doing). You do not want them because they can pack a powerful sting to small fish and invertebrates, and definitely to any corals that are near them.
With that said, it looks like you have a really nice tank there. Your rock looks very good as well.