AS3 and Canvas are alternatives. There isn't an AS3 Canvas type of FLA.
If you need it to be HTML5 Canvas, then yes, sound has to be Event and not Stream.
What do you want to publish to in the end?
Ok so right now I'm using a HTML5 Canvas but It won't let me change the sync in the properties. Im trying to animate something to a skit.
If you're going to end up with a video you should use an ActionScript 3.0 FLA, then you can set the sync to Stream. Even if it's going to end up as HTML5 you could create the animation as AS3, with Stream sync, and when it's perfect convert it to Canvas, and hopefully the Event sync will keep up.
Okay, Ill try that, thanks.