Workflow issue 2: symbols and reusing tweens

How do I best work in Flash CS3? I make web banners at work and it is important
to me that I can reuse and copy symbols, tweens and different animation between banners.

Is this the right workflow for this kind of work?

FOR IMAGE/VECTOR ART THAT I WANT TO ANIMATE (TWEEN OR ON MOTIONPATH)

  1. create symbol of the vectorart or image
  2. create the animation or tween INSIDE the symbols own timeline

FOR TEXT THAT I WANT TO ANIMATE

  1. Create textbox
  2. Convert textbox to symbol (1) and create my tween in this symbol
  3. In the symbol, create a new symbol(2) of the textbox
  4. In symbol (2) I change the text, if I want it to say something else
  5. In symbol (1) I change the tween or animation

TO COPY SYMBOLS BETWEEN WEB BANNERS
I open the old banner and copy the symbol and then paste it to the new banner

Is this the best way to make web banners and to easy copy and paste symbols with tweens and other animations?
Or is there any better way and more practical and timesaving?