Best use for dynamically manage objects from library?


My questions :

1)What are the pros and cons of dynamically targeting/managing movieclips from the library with syntax like :

var myMC:BlueCircle =  new _myMC();       

2)Would you suggest still using the Flash stage to organize movieclips easily and targeting them with their instance names OR adding them to the displayList via an .as file one after another with their x/y position, … ?

  1. What would be the easier way then, if you want to center a global MC on screen, which is made by many subMC’s that still needs to be targetted ?

Thank you !!