The length of the DBFZ story can be subjective. It includes multiple arcs and character developments, which can make it feel quite lengthy for some players, while others might breeze through it.
There probably is. Fanfiction is a vast world where all kinds of ideas are explored. Since Naruto and Jiren are from different anime universes, a fanfiction about Naruto being a fan of Jiren could be really interesting. It might involve Naruto somehow learning about Jiren's power and being in awe of it. Writers could play around with different scenarios like Naruto trying to train like Jiren or even seeking his advice in the fanfiction world.
Yes, it is. DBFZ Story Mode has many characteristics of a visual novel. It presents the story through a series of visual elements like character illustrations and backgrounds, along with text - based dialogue and narrative, which are typical features of a visual novel.
I don't have the exact number off the top of my head. But you can usually find that information on dedicated gaming wikis or by reaching out to the game's developers or community managers.
Well, the length of the DBFZ story in chapters can vary. Sometimes new chapters are added, and it's hard to give a fixed number. Maybe you can search on dedicated fan forums for the latest info.