I have a example of what I think you want http://www.cybermountainwebservices.com/client0/date/

the code:

// com is the instance name of my FLVPlayBack component.
// it is the only thing placed on stage at author time
//btnHolder is a movieclip in the library that holds the
//buttons which are also MovieClips
//initial size of the video 320 X 213 which also the
//initial size of the stage

package
{
    import flash.display.*;
    import flash.display.BitmapData;
    import flash.display.IBitmapDrawable;
    import flash.media.*;
    import flash.events.*;
    import jim.interactive.*;
    import btnHolder;

    public class WebSite extends MovieClip
    {
        var mesolve:Dissolve2; // Dissolve2 lives in jim.interactive
        var holder:btnHolder;
   
        public function WebSite()
        {
            stage.align = StageAlign.TOP_LEFT;
            stage.scaleMode = StageScaleMode.NO_SCALE;
            holder = new btnHolder();
       
        addChild(holder);
       
        var onStage:*;
        onStage = com;
       
        var ratio:Number;
        var rRatio:Number;
       
        ratio = onStage.height/onStage.width;
        rRatio = onStage.width/onStage.height;
        var newRatio:Number;
       
        function fillBG(evt:Event = null):void
        {
           
            newRatio = stage.stageHeight/stage.stageWidth;
            holder.x = stage.stageWidth - (holder.width +25);
            holder.y = 50;
           
            if (newRatio > ratio)
           
                {
                 onStage.height = stage.stageHeight;
                 onStage.width = stage.stageHeight * rRatio;
                }
                else
                {
                  onStage.width = stage.stageWidth;
                  onStage.height = stage.stageWidth * ratio;
                }
        }
        fillBG();
       
        stage.addEventListener(Event.RESIZE, fillBG);
        // ************************* buttons ***************
        this.holder.mcContact.buttonMode = true;
        this.holder.mcContact.addEventListener(MouseEvent.CLICK, gotoContact);
       
        function gotoContact(e:MouseEvent){
        var canvas:BitmapData = new BitmapData(stage.stageWidth, stage.stageHeight, false, 0xffffffff);
        canvas.draw(stage);
        var bmp:Bitmap = new Bitmap(canvas);
        addChild(bmp);
        removeChild(com);
       
        mesolve = new Dissolve2(canvas);
        mesolve.addEventListener(Event.COMPLETE, nextPage);
        SoundMixer.stopAll();
        var contact:contactUs = new contactUs();
       
        function nextPage(e:Event):void {
            trace("nextPage");
            addChildAt(contact, 0);
            onStage = contact;
            removeChild(bmp);
            }
        }
    }
    }
}
// ************************ buttons end ************

In the publish settings under html tab set the dimensions to percent 100 100

In the html make these css rules

body {margin: 0; padding:0; overflow: auto;}

the buttons and text in my example don't change size but they're not stationary.  The var holder in my example is what holds the buttons as you can see it is set to change position as the stage width and height change. If you gave holder a fixed x and y  then it would remain stationary.

That's going to be a awsome site when you get the kinks out. The people in it seem very indecisive.  Getting all the processes to die when you load  a new swf is a pain AS2 seemed much better at that.  You should probably start a new discussion on that.

If you mean maximized browser no problem but as for full screen that's a different animal that I have no experience with.

About garbage collection you might find this interesting http://www.gskinner.com/blog/archives/2006/07/as3_weakly_refe.html

also http://forums.adobe.com/thread/103443?tstart=0 is useful.

If by "browser stuff" you mean issues you're having with the liquid full browser stuff then I should mention that when I was looking at your site I noticed that when I changed the width or height seperately it would take a while for your swf to react and fill in the space so you might take a good look at how I use the width to height ratios to keep everything smooth.  Your site isn't online now so I cant recall if the page has a 5pixel default margin around it or if in IE theres a scrollbar on the right thest css rules fill fix those issues.

body {margin: 0; padding:0; overflow:auto} I'll upload that site so you can play with it.