FWIW when I was experimenting with my flash game, I ended up with a swf file which #included a text file with all of the actionscript script, and hence could process the text file in a normal source control way -- I don't know if that's relevant for you.

That'd manage most of the convenience, certainly, but in my current setup I also get to manage the media resources (fonts, sounds, images or movies if I had any) in a text-based (XML-based, in fact) way; it's all diffable. Unless it should turn out that there is really no practical way to sort out my sound issues other than using the Adobe tools, "pay a load of money for software which manages to do nearly as well" doesn't have that indefinable air of a good deal about it for me :-)

Oh, totally, I'd agree with that conclusion. Just that they didn't have the specific (and possibly most glaring) flaw of not letting you source control actionscript.