The lobster will crawl all over the place and very aggressive during feeding time. No good to keep one as the crawls will disturb your corals and they won't open properly.
Take it out and use hyposalinity or copper. Sure cure if the fish don't die.
Meanwhile you might be interested to read thru this thread.
Question on quarantine to eliminate Ich
sometimes if the ich is too terrible then you can feed like hell but the fish just get thinner and thinner, cos the ich takes out more than what the fish can take in.
The ich will spread and your whole tank will kanna.
put your hands under strong lights and look for the shiny reflection. Might have some bristle stuck on your hands. I kanna before.
Using the hair method didn't get rid of all the bristles. Next time gear glooves
your fish also white spot outbreak right? I think all your corals normal normal ones so put them aside or look for LFS to hold for you 6 weeks while you drop the salinity to kill the bugger as well as to get rid of the ich.