The first pic is a Kenya tree (Capnella sp.) and the last one is a button polyp (Protopalythoa sp.) the one in the middle is a calcifying feather duster tube worm of some sort.
They are all very hard animals. They will all grow under subpar reef aquarium conditions. The two soft corals will take over and thrive under good light and water quality. The tube worm is a filter feeder. If there is enough food for him, he will reproduce.