2. When someone is sent into the past and the person they're sent into dies, they don't suffer the same fate. I can back this up because on the Escape Pod, Ellone says herself that "I guess it's not possible to change the future" or something like that, and if someone was sent back into the past and their vessel died they would die also which means the future would be changed, which is impossible.
I can back this up secondly because when Squall and Co. are sent into Laguna and Co.'s past they aren't controlling them, they're watching. We, the Player, are controlling Laguna, but we aren't an aspect in game so what Squall and Co. see is really jsut the past being played out like a movie, they can't change it.
Also, all that is sent into the past by Ellone is someone's consciousness (sp) and that doesn't really get killed physically.
Final proof for this point is that when Squall is in the past he doesn't feel Laguna's leg cramping, he can't change what Laguna is saying, he has no control...this is weak proof but it helps proove my point about dying in the past. (The reason Squall comes back KOd when Laguna is KOd in the past is merely a gameplay aspect, not a story aspect).