Can't access instances and functions in MC

Question

In this example, the code works fine on properties of a
dynamically generated MC (alpha, name, etc...). However, it fails
to access anything inside of the same MC (textFields, functions
etc).
Why?

Answer 1

You are not adding the content to the stage at 0,0, you are adding it to panel2 at 0,0.  THen you take panel2 and assign it to be something that likely doesn't exist by the time you assign it.  You need to wait until the loader completes loading before you attempt to do anything with its content, otherwise it has no content (null).  Similarly, you cannot control anything in the loaded swf until it has finished loading.  So assign an event listener to the contentLoaderInfo property of the Loader to determine when loading is complete, and have the event handler function deal with starting the interaction with it.
var myLoader:Loader = new Loader();
var url:URLRequest = new URLRequest("SWCS_S3_500x250_exp_panel_2.swf");
myLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, processLoadedSWF);
myLoader.load(url);
function processLoadedSWF(evt:Event):void {
    // deal with the loaded swf here
    // but you don't want to be assigning it to the panel2 object that contains the loader
As far as controlling anything inside the swf you load, is it an AS1/2 or an AS3 swf?