I was wondering, when I got my hairy mushrooms, I also got these worms that grow in long hard tubes. The only thing I hate about them is they emit this stringy slime whenever I feed the fish. What kind of worms are they, and are they dangerous to my tank? If so, how do I get rid of them?

They are vermetid molluscs which use strings of mucus to collect particles from the water for their food. They're not dangerous but the strings can irritate corals and the small species can multiply rapidly & take over most of the rockwork. Crush them or scrape them off at the base. Some hermits & true crabs will eat them, also copperbands and other nipping fish.