Pseudanthias pascalus and Pseudanthias tuka (both sold as purple queen anthias) have been the most challenging fish I have ever kept. They require a religious feeding schedule 3-5 times per day.
I am a sucker for taking tough to keep fish from my LFS that come in mistakenly or in place of something else. I had initially ordered Bartlett and Lyretail anthias but the wholesaler kindly sent purple queens (three of them) instead.

So while not obliged to take them I knew they would die if I didn’t, as they looked really bad. Their bellies were very sunken and one was pretty lethargic. The one did die the next day but happily the other two made it and have survived, grown and changed color.
So… would I ever intentionally buy one again…NO! These fish are extremely tough to keep and get to eat. At first I was hatching baby brine shrimp for them every day. Then slowly I weaned them onto cyclopeeze then frozen brine (that they still eat) To do this I had to feed an enormous amount of food, 5 times a day in the beginning and still three times a day now. Most anthias have very high metabolisms, which makes the frequent feedings a must. The weaning process seemed to speed up when I introduced a Bartlett anthias who readily accepted the frozen foods. I guess it was monkey see monkey do because the queens finally started to eat the cyclopeeze (yeah! No more hatching brine shrimp) Now I just throw in the food and they eat like pigs. On a side note there are a few articles that discuss the downsides to heavily feeding an anthias once or twice a day verses constant or multiple feedings. Oversimplified large single feedings creates a feast and famine situation that is unhealthy for the fish.
So I got the fish, got them eating, they have grown and for all intents and purposes have done very well. There are however several other problem that keeping the fish have created.
What do you think happened to all that uneaten food in the tank? You guessed it; it caused a huge water quality issue. Between the phosphates in the food and the extra nutrients from the uneaten food I had an enormous algae outbreak. Heavy skimming, more frequent and larger water changes, carbon, phosphate remover and my refugium couldn’t keep up. If I was going to keep the queens I was going to, had to, still have to put up with some algae. I picked a type that I could live with and let it “out compete” everything else. I have found a balance that isn’t too offensive to the eye (macros to coral/fish) but I would like to set up a species tank for them at some point.
This is the short version. Believe me it is a lot of work and there are many other beautiful purple fish that require a lot less work. I would recommend against getting one. Because of the special care and poor shipping records I think this is one fish that should be left in the ocean. JMO. If you want to keep anthias, Bartletts are much hardier and IME readily accept frozen/prepared foods.
I will try to answer any specific you might have.
SiF
PS While I didn’t mention tank size, like all anthias large mature reefs with a well-established pod population is IMO is a must.