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I'll agree with Kukuisa on #1 (pen shell) and #4 (boga).
#2 looks like a giant anemone - Condylactis gigantea
#3 is a maze coral (Meandrina meandrites) with its polyps out
#5 I'm guessing you're asking about the green semi-circles? They look like the macroalga, Lobophora variegata, but the picture isn't really clear enough to get a close look.