I do disagree with an all live food diet for dwarf lions (or any lions) but know that they are harder to ween then volitans. Yes it can be done (as many of us have done it), but I also know a friend with a common dwarf lion that he has fed rosy reds and ghost shrimp forever (a couple years) and it has bloomed into a beautiful lion. He is too impatient to take the time needed, but it should be done. I can see where a lfs wouldn't do it cuz they are just concerned with selling fish and not training fish (usually). The long term affects of feeding live food are not known, however not suggested. I personally look at it like this: Frozen food is like a person taking there vitamins every day and live food is not. And since I take my vitamins everyday, so do my fish (only they do it every other day). Just as there are big people who don't take vitamins who are healthy, so can be the fish who eat live food everyday. It breaks down into a whole lot of other microbiology/chemistry but this simple analogy is much more pleasant to understand. It doesn't necessarily mean the fish will die. Okay, I'm done babbling. Just my 2cents.
If anyone has seen studies proving that live fish feedings kill saltwater fish then please bring it to my attention. But from what I've read and results I've seen, along with a science major I'm not necessarily sure that it has ill effects. But rather it's just not as safe as frozen due to the fact that it comes from who knows where.