I'm not sure as I haven't read it. But it might have a special world - building aspect. The idea of a library on the other side of the mirror sounds very imaginative.
I'm sorry, I haven't read this light novel specifically. But generally, a light novel often features unique characters, an interesting plot, and may be set in a fictional world. It could potentially have elements like magic, adventure, or complex relationships.
In certain fanfic concepts, Naruto could learn Edo Tensei from Kabuto. Kabuto, having mastered the jutsu, might decide to teach Naruto for some reason. It could be because he sees Naruto's potential to use it in a more positive way compared to how he misused it. Naruto, with his strong sense of justice, would then try to modify the jutsu to be less evil - like not using it to bring back people against their will.
Hard to say. It could be on hiatus, but without concrete information, it's difficult to give a definite answer. Try following the mangaka's social media or the manga's official website for the latest.