Royce,
I feed mine usually 4 or 5 days a week. I don't think it is important to feed every polyp individually. They are colonial, and so when one polyp eats, all benefit. You could probably get away with once every few days, but I would make sure you give a lot when you do feed.
Sun corals are really neat. I'm so happy I got one, although it took nearly a week for all the polypys to come out and eat.
kris