Oooh...a new hot topic. It reminds me of some older threads. *cough* Heh. Anyways, here are my thoughts:
Basically, like others have said, if you don't want to feed live fish to your stock, then don't keep fish that need that kind of food. Stick with fish that can take frozen or dried food.
Ethical, moral—there can be a lot of words used to describe this issue, but that's just adding complex levels to a topic that doesn't need to be complicated. If we get further into the nitty gritty related to ethics, then why is there a group for keeping fish in glass/acrylic boxes? One can argue that it is unethical to keep any animal—fish, cats, dogs, rabbits, etc. But we still keep them, Why? Because we love animals and we want animal companionship, there is nothing compared to animal companionship. However, they do rely on us, and domesticated animals can't take care of themselves, so we have to provide them with the best food and care we can. If that means live food, then so be it, if it means dried/frozen food, then so be it. Either way, its about the animals rather than our personal feelings related to feeding them.
Long story short, don't try to sedate live prey, either throw them in or not throw them in at all. We are in control of our pets' diet; however, we also have control over what animals we choose to be our pets.
