But I ask you.If two eras were compressed it means TC happened in both.Not just in one of them.
So we conclude that the world of FF8 was already compressed.At least since the time Laguna went to Winhill up to the time Adel was defeated by Squall.
Well, the range you specify(from Laguna goes to Winhill to Adels defeat) WERE certainly in a compressed state for a certain amount of time, that's true, so that was a correct conclusion.

However, it is not correct to conclude that Time Compression was ever fully completed, simply because if that were the case, we couldn't be playing the game to begin with! So I'd grant you that what you're saying is correct to a certain degree, but your main conclusion is not.

Ultimecia says only she can live in TC.
But she is a villain and villains tell lies.
If she is saying the thruth then she lies when she says she can compress time in the conditions I to IV.
Firstly, it is not Ultimecia who says she can only live in TC, it is Rinoa and Edea, who basically read her mind while being possessed. This is how Edea knows about her entire plan to cast TC to begin with.

Secondly, where is the contradiction between your points 1-4 and the statement that only Ultimecia can live in a fully compressed timeline? Because as far as I can tell, there is nothing contradictory between the two.

By the way, I really don't understand you. On one hand you post nonsense theories in the most extreme sense, but then you came with this thread and manage to actually think of something which is within the limits of reason. Granted, your conclusion is still wrong, but good job anyway.