I do not understand why when I choose scaling page I can choose a anchor point but not when I want to change only the format of the document?
A simple change of the finished work containing multiple motion teewns 940x200 to 750x250 format becomes unexpectedly by way of torment. In many works I have spared a lot of time.
What's going on? As in simply and fast way to change the final composition?
use select multiple frames/layers.
Theoretically yes, but in practice — With many motion tweens Flash go wild and it is sometimes very difficult.
because it doesn't make sense
— Hmmm ... it makes sense to compose the scene immediately afterwards to manually re-set compositions in the center of the stage???