Well, they might be really shocked at the power levels of Goku and Broly. RWBY characters are used to their own kind of battles, and seeing the insane energy blasts and transformations in the Goku vs Broly fanfic could leave them in awe. They might start thinking about how they could incorporate some of those powerful moves into their own fighting styles.
In a Goku vs Broly crossover fanfiction, anime characters could have different reactions. Some might see Goku as a symbol of justice and be inspired by his never - give - up attitude. On the other hand, Broly's raw power could intimidate those who value brute strength. And there could also be characters who try to interfere in the fight for their own motives, like to stop the destruction that such a powerful battle could cause.
If anime characters are in awe, they might stay out of the fight and just be observers, which could keep the focus mainly on Goku and Broly. So the plot would be a more straightforward battle between the two.
Goku could escape by overpowering Broly. He might tap into his Super Saiyan forms, like going into Super Saiyan Blue or even Ultra Instinct if he's pushed far enough. His sheer power and fighting skills could allow him to break free from whatever restraints Broly has put on him.
One idea could be to cross UI Goku with a character from another popular anime, like Naruto. UI Goku could end up in the Hidden Leaf Village and have to deal with the different ninja powers and politics there. Maybe he'd have to train some of the young ninjas, which would be really cool as his fighting style is so unique.
Sure. Fanfiction writers have a lot of creative freedom when it comes to Goku and Female Broly. In some fanfictions, they might be in a romantic relationship, which is an interesting take considering their Saiyan heritage and the way they both value strength. However, not all fanfictions take this route. Some might explore a more platonic friendship where they respect each other's power and learn from one another. You can usually find a variety of these stories by using the search function on major fanfiction platforms.
It's hard to say for sure. Both Goku UI and Jiren are incredibly powerful in the manga. Their strength and skills are on par, so it could go either way depending on various factors.
First, decide which character or universe you want to cross UI Goku with. This is crucial as it will set the tone for your whole story. Then, think about how Goku gets to this new world or meets the new character. It could be through some kind of interdimensional portal or a magical spell gone wrong.