Important questions about zebra danios!

I think they are easy to breed but they lay eggs and usually egg layers don't breed in community tanks since other fish keep eating their eggs. I have never had them breed in any tanks I have kept them in so I don't think you need to worry about it.

I think they need shallow water to breed. They are a great starter fish as they are practically unkillable but you will likely gravitate away from them after a year or two as they are just too active which is unsettling to the more placid fish. See if you can find celestial pearl danios, they are much prettier.