Hehe, Actually I think it takes alot of work to breed any marine animal and I respect those that do, do it. I just think the more you understand the fish and inverts in your tank. you can probably be a better keeper. Anyone can have a fish and feed it, but not everyone can keep them alive for years like alot have done on these boards. You can probably live without clean up crews but your going to be doing a hell alot of work on your own.
When you see crabs in the wild, how many are in one area? Say 50 square feet. How many shrimp? And so on. Choosing the right balance is probably crutial, and the cause of alot problems. Like crabs, you have to take into consideration, will your living system sustain "one"? If you don't have enough of thier natural foods or supply them. They will go after the things you don't want them to. Now I don't know much about them, so I could be totally wrong. They could just be as bad as people say they are.
How big does an emerald crab grow in the wild?