I have had a great deal of success with my stars but I do a few things different. One I use TBS sand in the tank, sump and refuge. Rarely have I ever lost one I do keep them out of the sump and refuge and I suspect those areas feed the tank since they are left undisturbed by preditation. I also notice that the large carpet I had did very well in this type of setup.
My only logical conclusion was the other areas were feeding the main tank. This setup also produces huge numbers of pods and some as big as 3cm as well as numerous brittles.
I would not recommend stars in anything but a well established tank, they are opprotunistic feeders and typically I hold to the belief that often they can not compete for food except in heavily fed tanks.