This forum is 6 years old but just in case someone had the same problem as me, I want to help them! I tried using Kurst to export my animation to a png sequence and it worked well EXCEPT it ignored the actionscript 3 vcam I had in my scene, and instead just showed the whole stage for the entire duration of the animation.

After searching, I found this program: Swivel. It is free and exports a swf file using the actionscript 3 vcam flawlessly. It only allows you to export to video format (even though I prefer png sequences) but it allows you to export a lossless video so that was really not a draw back.