On my venture for quick rendering within Flash, I’ve worked out that the only solution is to create sprite sheets on the fly.
Sprite sheets are created from a MovieClip using BitmapData.draw().
I have a graphics manager class which has a method that accepts a MovieClip and an int. The MovieClip is the target to capture graphics from, and the int represents how many different angles the image can be rendered at within 360 degrees.
For example, if the int provided is 4, I’ll get this result:

And if I provide 8 I’ll get this:

And so on (up to 360).
The method then returns an instance of another class I have created which will allow easy capture of the BitmapData of a given cell by specifying a frame and rotation, for example:
var myGraphics:SpriteSheet = aboveMethod(movieClip, 4);
var cell:BitmapData = myGraphics.getCell(2, 90); // frame 2 rotated to 90 degrees
Creating these sprite sheets is obviously going to devour a lot of RAM – especially if I have something with 100+ frames that needs to be rotated to the nearest 2 degrees (1800 cells total).
I have no idea how much RAM these use, and I have again no idea how much RAM is satisfactory for my game to be using.
Any advice around this would be extremely helpful. Note: I have made sure to utilize BitmapData.dispose() within my own dispose() method defined by SpriteSheet to clear up RAM, I am more concerned about how much RAM I can use at one given time (all game assets that will render ready to be used).
Perhaps utilising one of these within your code will give you some useful feedback.
https://github.com/theflashbum/stats.as
http://demonsterdebugger.com/