Wow. Well, I'll try and refrain from writing a book for you here...that's what Flex 4 in Action is for
In short, with the release of AS3 in 2006, ActionScript became a mature, object-oriented language with a lot of its roots coming from
Java (this is generally the reason Java devs find it a lot easier to pick up Flex and AS3 than those that come from non-Java backgrounds). AS3 is both statically and dynamically typed, but best practices must be taken into account when using the static keyword. In other words, if you're going to declare something static,
you should have a good reason to do so, otherwise we leave it dynamic. Animation is where AS3 excels (in my opinion) above all other languages since it was originally created specifically for the purpose of creating animated content for the web. However, that was about 12 years ago, and 12 "computer years" is quite a long time... We now have an abundance of open source frameworks for 3D, Physics engines, and the like. Off the top of my head, the obvious ones to look at would be: Papervision3D, Away3D, Flare, Axiis, and well, I could probably go on until I'm blue in the face. Its not hard to find these code libraries as there are very active communities surrounding them.