Just press reset at fakecarrier, it will change back to original carrier name.
I use TFW and want to change to AT&T, it doesn't work because they are both to use same network. I need to add a dot to AT&T. Then it works.
no, it can't "change battery level". as in the screenshot, on 7.0.4 on iP5, the only option available is FakeCarrier. both Fake Time and Show Battery Level are grayed out and unusable.