It's going to be a couple months at most. If it's not punished immediately, it's practically legal with the current gov. And the next one will have way bigger things to unfuck than some missing documents.
My understanding is that anyone can sue anyone in theory. Ideally, yes.
In practice, the State AG's are one of the most respectable powers to sue for a federal law being broken, which would then go to federal court. Ideally the SCOTUS would step in itself and injunction all this stuff so it doesn't get to this point, but Trump sure is working them overtime.