1 -- looks like a nudibranch. I would say sea cucumber or sea hare, also. Is it some sort of slug? If so, most nudibranchs are not reef safe and it's very difficult to say what kind it is exactly since there are so many types. Google sea hare, if it is one of those guys, it's reef safe but will starve to death in a tank without enough algae.
2 -- hmmm, some sort of anemone. Maybe a rock flower anemone. It doesn't look like a typical pest anemone (aiptasia or majano) to me, but I could be wrong. I'd keep an eye on it. If it starts to spread and make babies, kill them all. :lol: If it stays singular like that and just grows, it's probably not a pest.
3 -- I don't know what I'm looking at in this picture. The tube at the top of the rock? Or the red stuff?