The browninsh red algae is most likely cyano, but don't kill it with chemicals, find out why it's there and eliminate the culprit. Ammonia and nitrates would be the first thing I'd work on fixing.
As far as your protein skimmer, you may have a brand that does not work so well. For example seaclone, some people love it and others say it does not work at all for them.
As far as your sebae, I could ask you a million questions such as your lighting, your water flow, your feeding schedule, but in the end I will not know the answer... But I'll tell you who does. The folks in the "clownfish and anemones" forum!! Be prepared to answer those questions and post a pic if you have it.
HTH