While working with your component I faced these issues.

1. I can’t add components using Repeater in it, At last its a container, why is not happening.
2. I can’t add childs dynamically through action script.

I can add component using data provider to it, and need to mention ItemRenderer.
Why so ? Can’t I add different components to it.

So, I did a small work around I don’t exactly know in which case it will break your code, but for know its working fine.
here is the code.
protected function buildFromDataProvider():void
{
itemContainer.removeAllChildren();
for(var i:int=0;i<calcMaxItemScrollBy();i++)
{
if(dataProvider[i] == null)
throw new Error(”your trying to add null object, which not supported”);
if(_dataProvider[i].height == 0)
throw new Error(”please mention the height of component”);
if(_dataProvider[i].width == 0)
throw new Error(”please mention the width of component”);

addScrollChild(dataProvider[i],false);
}
//invalidate list
invalidateScrollList();
}

Regards,
Imtiyaz

Cheers