The one's on the left are Button Polyps (Protopalythoa species), the one's on the right are Zoanthids (Zoanthus species) - good times.
The final pic looks like Aiptasia to me - bad times.
The star you mention sound like either baby Brittle Stars, more good times, or Asterina Stars - bad times but some are fine.
Don't know about the blobs and brine - need another description
~ Paul