unfortunatly your not going to like the answer to the id question. That appears to be a aptasia anemone which is a pest. They will reproduce rapidly and sting and kill other corals. Best advice is remove it now before you have more problems
Another Thing If I use Aptaisa -X This Pest is right below a Micro Star That has made the inside of the rock a Home Will it hurt the Starfish above him any?
Best way to rid the rock of it is to remove the rock, take a lighter and burn it off. No other way can guarantee it doesn't drop any spores to reproduce. Good luck!
Can't guarantee anything of course you could have more near it, but in general removing the rock momentarily and contact burning the tasia off should result in no spores because its not in your tank and anything that may drop is harmless.
its not aptasia those are more related to dendros than aptasia. dont kill it feed it mysis. if you touch it and see when it reseeds youll see it goes in to the rock and youll see its structure .if you touch aptasia itll turn into a ball like an anemone which it is.