I'm about to undertake a fairly advanced/complicated animation involving 30+ transparent .PNGs to animate a character and I was wondering the best approach for it?

Two options:
1. Animate in After Effects and export an FLV into Flash where some interaction, etc, may be added. Final export as SWF.

2. Animate completely in Flash and export as SWF, I'm worried that this may become too processor intensive/choppy?

I'd like to go with option 2, but does anyone have any experience with a fail safe backup if the animation becomes too choppy/intensive? In theory, could I animate in Flash, then export to images, then build an FLV from it (reverting to option 1 a little but with no use of After Effects), then re-import the FLV and export as a SWF again?

Any thoughts or advice would be much appreciated!