You wrote, "another memoire, he states that before the battle - both Berthier and Daru - pointed out, that in case of need to retreat the plan the situation for evacuation at Leipzig was very bad and dangerous for the army, Napoléon didn't like to hear that. "
N. is reported to have reconnoitered the area, so he knew the tactical situation. N. felt that he didn't need advice. Hard to argue with that, really.
You wrote, "I find it strange that Berthier should get the blame, whose advice was ever so often ignored by his master. "
According to Thier , it was the historical revisionists -in their zeal to absolve N. of all errors- who came up with the story to blame B.
You wrote, "So the premature blowing up of the bridge and the defection of the Saxon as well as Berthier are the main culprits for the loss of the battle - obvious propaganda tricks to shift the blame away from NtG. "
In the report on this event in the bulletin of the GA, only the premature blowing up of the bridge is to blame. If the bridge was blown just as the rear guard passed -successfully pulling the French Army mostly intact out of the great battle- and by denying the Allies any chance of hot pursuit it would have been reported as "French Army Victorious: N.'s genius miracle escape of Leipzig"
The bulletin of the GA are, of course, propaganda but it's N.'s personal propaganda. It's his view of the situation. Only N. could tell the copyrighters what to write.