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.
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.
For Yamcha, you can focus on his growth from being a bit of a comical character to a more serious and respected fighter in the context of his relationship with Frieza. Maybe he learns from Frieza's cold and calculating nature how to better strategize in battles. For Frieza, his development could be about him learning to care for someone other than himself. He could start to see Yamcha as an equal, which is a huge shift from his usual superiority complex.
You can also make him have a unique role in the story. For instance, he could be the one to discover a new threat to the Earth before anyone else. He then has to convince the other Z - Fighters to take this threat seriously. This would put him in a leadership position and make him stand out more.
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.