I think zoas are fairly easy to care for. You don't need to feed them anything, but a few claim feeding phytoplankton will increase growth. I think they can tolerate all kinds of flow, as long as they're not getting blown off the rocks. Same with lighting as long as it's not too extreme. If you put them too far down at the bottom, they will stretch and grow taller. If you put them at the top, they will stay very short and flat. To sum up, I think they're very adaptive and hardy, you just have to watch out for pests like nudis.
Another thing to watch out for is that they contain palytoxin, so handle them with care. Someone told me that the plain brown or green ones are more toxic than the colorful designer ones, but I have no proof to back up that claim.