Try SourceTec SoThink SWF Quicker (I think), it comes onto Giveaway of the Day (
http://www.giveawayoftheday.com/) every once in a while. It's a lot like Flash with minor UI differences, and it supports Action Script (via a UI window in the lower right, not via the right-click on keyframe method in Adobe's Flash), so it's worth a shot.
Plus, it's budget priced, and I've never had any problems with it for animation (though, mind you, not Action Scripting).