Wow, unreal that she could approve such a warrant. Even in the absence of a federal statute it seems like a crazy step to take.
0 - this is as close to absolute immunity as exists in the law. In fact, you could, with a straight face and clean conscience call it absolute immunity.
1 - no, seriously. They can, for instance order an underage girl to be sterilized in an ex-parte hearing and face no consequences. https://en.wikipedia.org/wiki/Stump_v._Sparkman