Honestly, comparing the strength of anime Goku and manga Goku is tricky. Both versions have their unique strengths and challenges depicted differently, making it hard to make a clear-cut comparison.
Some Dragon Ball - themed forums also often have sections dedicated to fanfiction. Members share their own works or recommend good ones they've read. For example, the Kanzenshuu forums might have some great Goku and Black Goku fanfiction.
Well, Vegeta would be a likely character. He might be initially suspicious of the female Goku. Maybe he thinks she's a threat or just can't believe there's another Goku - like being. He could be there to add some comical moments as he tries to understand the situation.
One good fanfiction is 'The Blackened Saiyan' which explores Goku Black's journey in an alternate universe with a lot of in - depth character analysis. Another is 'Goku vs Goku Black: Redefined' that has some amazing power - up battles between the two. 'Black's New Purpose' is also great as it gives Goku Black a different motive than just pure evil.
One popular 'goku x female goku black fanfiction' might be 'The Unlikely Bond'. It explores a unique relationship between Goku and Female Goku Black. In this fic, they start off as enemies but gradually discover they have more in common than they thought.
With Gine, her character can be developed by exploring her feelings towards Goku. She could be shown as a loving and proud mother, but also with a sense of sadness for all the years she missed with him. Her interactions with Goku could bring out her more maternal instincts, and she might start to see Goku as a symbol of hope for the Saiyan race.
In general, it's a bit of a toss-up. The strength of Manga Goku and Anime Goku can vary depending on the specific arcs and battles. Sometimes, it might seem like one is stronger in a particular situation, but that could change in another.
In a Gohan x Goku fanfic, their relationship can be delved into by creating scenarios where they have to rely on each other completely. For example, if they are in a situation where Goku's strength and Gohan's intelligence are both required to escape. Their different personalities can also be highlighted. Goku's carefree nature contrasted with Gohan's more studious and responsible side. And of course, flashbacks to Gohan's childhood and how Goku's presence or absence affected him can add depth to their relationship.