cacheAsBitmap is not a “miracle” method to save processing power.
When you enable cacheAsBitmap, it takes the object and processes it, saves it as bitmapData, and this means it can move it faster. (instead of calculating vectors every frame).
However, this all goes out the window when you
especially over many frames. Everytime something is changed, it is forced to re process the data. And not only that, now you will have to reprocess it AND save it as a bitmap. That’s quite a performance hit since they’re doing twice the amount over each frame.
So make sure you’re using it in the right situations.
As for a blitting engine, here is one for AS2
and his sequel for AS3
edit: I can’t make a list :S