Coral and starfish identification

[novajoe]

Hello everyone,
So couple things
1. When I got this tank 2 years ago my friend who had it had this coral in it unfortunately when I got the tank it was covered in algae and pretty much died. Being new at the time I couldnt save it.
But I kinda want to get this again.It was a deep deep purple.

2. I just bought this from the $16 section at my fish store and it wasent labeled. I assume it was like an acropora, if it isnt.

3. This dude came in on the new coral.
Trying to figure out safe or not dont know about star fish really. Just thats its a brittle star.


The pictures are in order.

 

[Gumbies R Us]

Looks like a brittle starfish. Those are good cuc to have

 

[Mr. Mojo Rising]

The dead coral looks like an acropora, impossible to know what kind.
The coral looks like a type of branching montipora.
The starfish is a brittle starfish or a micro brittle starfish if it is the size of a coin, I can't tell the scale in the picture.