I never said Zidane should hate Kuja. All I did was point out the relationship between Kuja and Zidane. And in fact, Kuja was supposed to be the one who hated Zidane, not the other way around. Zidane was created to be smarter, stronger, and all around just plain better than Kuja. Kuja hated and loathed the fact that he could be so easily replaced at the whim of Garland, and it's Kuja's hatred of both Zidane and Garland which drives him to do the things he did.
Zidane was so hell bent on beating Kuja because he saw the pain and suffering Kuja was causing his friends. That's a big part of Zidane's character (whether people will admit to it or not, but I'm not going to argue that point), he generally cares for other people. Does he think of himself before other people sometimes? Yes. All sentient creatures do. But when his friends need him, he's there. When Garnet is in trouble, he goes to her. When Armarant doesn't come out of Ispen's Castle, Zidane goes to check up on him. When Freya rushes to Burmecia, Zidane opts to go along. When Vivi needs cheering up, Zidane does his best to get the job done. So while he didn't have all the personal motives of revenge for going after the bad guy like all the characters you listed, Zidane instead does what he does to support his friends, and because he knows its for the greater good.
And as far as Garnet and Vivi go. You ask if anyone really liked the Queen Brahne. Garnet did. Garnet loved Brahne even after finding out Brahne wasn't even her real mother. Just because the Brahne we see in the game is cold hearted, doesn't mean she was always that way. In fact, Garnet and some of the citizens of Alexandria outright say that the queen was a caring and compassionate woman before her husband died and Kuja started manipulating her.
As for the black mages, we have approximately two dozen of them who gain self-awareness and seek solitude to learn and grow. Except that they were created witht he curse of having severly limited lifespans. They grow to understand that stopping equates to death, and have to learn to try an accept that, an issue Vivi also has to understand. Enter Kuja who tricks and manipulates these sentient beings with alluring promises on extending their lives, and many of the mages are tricked into believing him until they realize his lies after he treats them like utter cannon fodder the entire time, and at the end of their usefulness to them, laugh and insult them calling them fools for being so easily manipulated despite the fact that they have the minds of children. That is what the black mages essentially are: children. And that's plenty of motivation for Vivi to stop Kuja.
