A:AnswerYes, this is compatible with consumer cellular, as they are for the most part of the AT&T networks with some t-mobile networks mixed in certain areas, and this supports all the required frequency bands.
A:AnswerIf the second sim only supports 2G, then the second line will not work on AT&T network (no voice or data). I think T-mobile still has a 2G network, so it may work there.