Nope, not really, what happens is like this: the document class is a sprite,
which has some code in it, which is called first in the application and this
class is automatically added to stage, if it is not loaded. However, if the
SWF is loaded, then the class isn't automatically added to stage, however,
the constructor is executed before that.
Now, Flash will create variables and assign the library instances to those
variables if you put those instances on the stage, however, if you turn off
the "automatically declare stage instances", Flash will not create the
corresponding variables for them (and so you will get an option to define
them yourself in your class. You don't need to initialize those variables to
anything, Flash will initialize them to the timeline placed instances of the
same name.
