I think the "another green thingy" is called Mermaids cup (Acetabularia sp.) from what I can tell from my reef inverts book. Apparently they really fluoresce under actinics and is described as "a real treasure in the marine aquarium". Needs bright warm light and moderate water flow, while avoiding strong or linear movement. Looks pretty delicate to me.
Hope that helps. I don't know what the other things are but I bet as they get bigger we can figure them out.
Christy
