Gohan hated Cell. He hated him before he got control of his emotions and he hated him after. Hating him and killing him didn't poison his mind forever after. Considering the things Dandeer has done, Kakara's wishing for her death is justified. If we give her mercy despite the great evils of her crimes, that's effectively setting a bar that'll prevent her from killing villains that need to be put down because "It's not more evil than what Dandeer did and I argued that she should live for the sake of mercy".
No, Kakara wishing for Dandeer's death is not justified unless trapping Jaffur in his own mind was the
intentional result of the sealing rather than a side effect of Jaffur being sealed while Super Saiyan. If Jaffur had just turned into Jaron rather than Jaron being a separate person, Jaffur would be better of now than he was being abused by Lord Vegeta (of course, he'd be even better off if Vegeta got sealed while Jaffur don't, but still).
Now, on the other hand, I wouldn't fault
Jaffur for wanting Dandeer dead, as he's the one who got trapped in his own mind by her (intentionally or not), and either way, he and Lord Vegeta (if he gets unsealed) are the people with the actual
authority to punish Dandeer.
Considering Gohan, Goten, and Trunks were all raised and treated as Human, instead of raised and treated as a Saiyan, that's not really saying much.
Goku was
also raised and treated as a human, yet he
did possess a Saiyan lust for battle. Sure, the modern (hybrid) Saiyans may be culturally disposed to fighting, but that's not the same as being born to yearn for battle.
Vegeta getting Mindwhipped? I can understand that. Jaffur though? Fucking hell no. She was so busy freaking out about Jaffur lossing his shit about Vegeta getting mindwhipped she couldn't even bring herself to ask her son WHY he was so pissed before going 'Nope. He needs a mind wipe too'.
She was quite clearly
panicking. First her husband almost kills her son, and then (at least in her mind) her son almost kills
her for saving him. Thanks to the rationalization she made up for why Vegeta was abusive (his "tainted heritage"), she then concluded that the only way to have Jaffur live a happy life was to seal him (and, well, Jaron seems
much happier and mentally better off than Jaffur, so if it wasn't for the fact they're not the same person and Jaffur ended up trapped in his own, I could actually see her point). None of that gives her any right to seal Jaffur, mind you, but she didn't have any bad intentions (again, this is assuming Jaffur being trapped in his own mind was an accident. If it wasn't,
fuck Dandeer).
And again, the only one with the right (both morally and legally) to decide what happens to her is Jaffur, not Kakara or some religious cult wanting to burn her for being a heretic.