Also, your static time theory doesn't bode well with me. Ultimecia manipulates time in the game, so time is by no means purely static or linear throughout the game's plot.
I disagree. Ultimecia's supposed changing of the past can merely be seen as another event set in stone by the fate constantly referred to in the game. One may see her as simply fulfilling her 'destiny' and that in reality, nothing is changing through all the time-travelling occuring in the game (ie. Ultimecia's presence in the past has always been an immutable event on the line of time, along with the event in which she travels back in time).

However, the discussion of whether or not time is static or dynamic is still one which is left open. I advocate static time, and can use it to explain everything in the game pertaining time-travelling. On the other hand, dynamic time can also be used to explain everything. I merely advocate static time because I believe it is the simpler and more elegant theory. My specific views on the matter (along with a dynamic time explanation as well) can be found in the FAQ I know you are familiar with, so I won't discuss this further here.

The rest of your arguments rest on changing the past, and since I have already made myself quite clear in previous threads what I think of your scenario, I see no reason to argue further on the matter. All my own views can be found in the FAQ previously referred to anyway.