Its interesting because I've had one for some time now. I used to feed it every other day. I got lazy and only fed it once a week. I got even lazier (well, got busier at work stayin super late) and now I feed MAYBE once a month. Honestly, I probably only fed it once in the past 3 months. It only opens up super big when I feed it. Otherwise it opens "normally" when I feed the fish. No signs of tissue recession.
I dont think that each-and-every-polyp needs to be target fed but you should try to get as many as possible. I think they are pretty hardy once you get them to a fairly healthy stage. The "feeding hat" method is a neat idea but doesnt work for me due to limited space. I actually take the coral out, into another container of tank water to feed. Then I place it back in the tank. This keeps the other critters from stealing its food and prevents the water from fouling from uneaten food.
Also, keeping it out of light is recommended only to keep algae from growing on it. The light has no effect on the coral itself. Mine is in an unshaded location and is doing well.
