You're saying that the antagonist's claim that it's not done charging is proof that it can be charged in Super Saiyan, despite Goku not being in Super Saiyan while he's charging it? How does that make even an iota of sense?
Krillin says that way before he makes that face and that was after waking up and seeing a Super Saiyan Goku with a Spirit Bomb. It's entirely reasonable to suggest he was mistaken and thought incorrectly that he formed the Spirit Bomb while he was Super Saiyan. It also proves that, at least as far as the characters know, the Spirit Bomb can only be formed by those pure of heart.
Considering her hatred is very literally maximum when it comes to Dandeer, I think it's safe to say that Kakara's heart is at least tainted with rage. Furthermore, simply being kind and a pacifist doesn't make one pure of heart. She could still have a tiny amount of evil despite that and considering Kami's thing, it's very likely that she would.
Maybe instead of using
some of his vital lifeforce like the other times he used the Tri Beams, this time he completely on purpose used
all of his vital lifeforce to kill Nappa. The only difference is the quantity of vital lifeforce he put into his attacks.
Never said it was.
And? What's your point?
If it were just any limitation you'd be right, but this is a limitation we chose to place on ourselves to encourage us to take the route of non-violence. That is its purpose. Circumventing this limitation for the purpose of allowing us to be better at violence goes against the point of the limitation in the first place. If we want to increase our capacity for violence, we should take it square on with the penalty in tow, otherwise it provides no disincentive for violence.