They are similar to zoanthids.
Protopalythoa commonly called button polyps.
Bubble algae is considered bad.Emerald crabs and maybe some other invert may consume them.You also can manually remove them,avoid bursting the bubble.It will just help make them spread.
You also have what looks like a little leather,maybe a toadstool.It's hard to tell for certain since it's so small.definitely a leather,nice score.