Actually, where does it state that if you kill someone who has a viewer inside, they die? If you want to use Squall in Laguna as an example, think again and consider the paradox involved.
Now matter how weird that sounds thatīs what happens.
We SEE the characters taking the damage back.
PS:Maybe it was a proof that time is not set in stone?

And Ellone doesn't send Ultimecia to a person in past that dies, the game says that Ellone needs to send both Rinoa and Ultimecia to a Sorceress in past to make Time compression possible (if my memory is right)
I donīt said that.
I said that Elone can easily send Ulti to the past inside a person who dies before the present day WHEN SHE MEETS EDEA.

That way Seedīs creation is not necessary anymore.
I am not only talking in the Pandora.
I am talking everytime Edea looks for Elle and find her.

If you think a little what makes sense is Edea trying to scape from Elle after Elle knows she is doing evil things(not the opposite).