There are two varieties of Asterina starfish. IME, 95%+ of them are harmless and eat nuisance algae. I have a tank FULL of them. 5% or less of them are the type that eat corals. They only eat hard corals and coraline algae if they do...
There is some coraline growth starting to come through though, so I guess I'll just have to watch for it vanishing... 
Give 'em a couple of weeks to get used to the tank and they'll be as bold as my Discus, but hopefully not as bold as the Tomarto Clowns that used to be in work's reef display. They drew blood on my ex-supervisor





The mistery frag is under a strong bit of light ATM, so if it is a hard coral, it should do OK and be properly become properly ID'able soon. It has not moved from where I put it, so I further suspect is isn't a mushroom (so far they have all ran away despite many attempts to stick them somewhere on show).

