I must use "stream" because the video must sync with audio.
Suggestions I found on Google:
1) Use Event mode. I am aware the "Event" mode will play over multiple scenes, but it does not force audio sync, which causes major problems with audio sync.
2) Don't use scenes. This is what I'm working on now, but it's a nightmare solution - trying to transfer many layers from many scenes so they all line up again.
I would even be open to trying other software, but flash is the only vector animation program I've found that allows for easy animation and freehand vector drawing (unlike Illustrator-type programs that make you take all day dragging curve points).