Resizing/moving MovieClips to fit screen problem

I'd like to make an Android and iOS app with Adobe AIR, but I found a problem I can't solve.

The Flash document size of the app is 800px x 600px, and I'd like to resize MovieClips to fit Android's and iOS' screens, suporting the Retina display on iOS devices.

I tried using StageDisplayState.FULL_SCREEN and StageScaleMode.SHOW_ALL, and this does seem to work with static MovieClips, so the snippet would look something like this:

import flash.system.Capabilities;
import flash.events.Event;
import flash.display.StageScaleMode;
import flash.display.StageDisplayState;
stage.addEventListener(Event.ENTER_FRAME,process);
var difN:Number = (((stage.stageHeight*stage.fullScreenWidth/stage.fullScreenHeight)-stage.stageWidth)/2);
function process(e:Event):void {
          difN = (((stage.stageHeight*stage.fullScreenWidth/stage.fullScreenHeight)-stage.stageWidth)/2);
          stage.scaleMode = StageScaleMode.SHOW_ALL;
}
stage.addEventListener(KeyboardEvent.KEY_UP,useFullScreen);
function useFullScreen(e:KeyboardEvent):void {
          if (e.ctrlKey) {
                    switch (e.keyCode) {
                              case Keyboard.M:
                                        stage.displayState = StageDisplayState.FULL_SCREEN;
                              break;
                              }
                    }
}
obj.x -= difN

However, I'd like to use classic tweens in my application, and this won't work since most of the elements are moving.

I'd like to rescale/move MovieClips so they don't look distorted and every moving item moves correctly, showing all the content and trying to not make any borders. I read this article but it seems like it doesn't support classic tweens: http://www.adobe.com/devnet/air/articles/multiple-screen-sizes.html.

Thanks for the help.