You may want to find a way to make the pictures smaller.
I'm not certain what the 'tube snail' (slug) is, but the bristleworm is good. They creep into tiny crevices and eat gunk that nothing else can reach, and they're part of a healthy reef. Also, it's virtually impossible to eliminate them without boiling all of your sand and rock. Just leave them alone, they're basically saltwater earthworms.