And these some characters that lie result into a complete change of plot in the game and I can also say they didn't lie, ya?
Exactly.It results in a change of the plot.

Go analysis the game without just looking at the game graphic itself and pay attention to other stuff. Like the in game dialogue or check out the FF VIII Ultimania Guides like Squall Of SeeD do. Go ask him about stuff about Ultimania Guides.
Believe-me,I have playing the game for about 6 years and analysed everything.Events,graphical details and script.
What is this Ultimania guide?

And yes,I know a hint can have different interpretations.But this is exactly the fun.
And when there are MANY different hints the broad of possibilities get narrower.

Let me pay a visit to this Arts and Writing forums.