Second: Are you talking about pure breds or hatchery "Ameracaunas" that are actually Easter Eggers (EEs), which are technically mutts?
Third: If they really are EEs then it depends on the bird, as they are mutts. I love EEs though.
Um... NO. Most don't even live that long. Usually they slow down in laying after 2-3 years, and after that only an egg once in a while. Of course some are the exception and go on laying but for most they stop after a bit.