Help ID this worm and his friends

[Ross]

Hey

I'm having a bit of a hard time identifying these few items living in my tank
Any insight would be of great assistance.

Item 1
These inch to 2 inch long clear spiked threads are attaching themselves around the tank in all levels of light and flow.
http://farm3.static.flickr.com/2704/...d14f22d5_o.jpg

Item 2
There are several of these worms in the live rock. They go from one hole to another and from time to time you can see stuff moving inside them. They are about a mm in diameter and are round.
This pic http://farm3.static.flickr.com/2592/...102a5882_o.jpg it is empty.
This pic, it is not. Note the yellow stuff moving down the tube.
http://farm3.static.flickr.com/2612/...36f219fa_o.jpg

Item 3
Is to the right of center. It's a small purple flower shaped coral?
Its rather small, but they seem to be spreading and i dont know if I should pull them before they spread much more.
http://farm3.static.flickr.com/2750/...73434f28_o.jpg

Item 4
Is about the size of a pea.
http://farm3.static.flickr.com/2651/...a8c42a4d_o.jpg


Thanks