I didn't get the "in the beginning" thing. But if you want to hide the FLV controls and the buffering, you can use,
Media_instance.skinAutoHide = true;
In this way, you get he controls only when you hover the mouse over the component. Which means you will not see the buffering or controls in the beginning.
But if you are looking for a permanent removal of the Controls and the buffering bar, you can use,..
Media_instance.skin = none;
In this case you will never see the buffering and the controls, even during the hover.
Hope this answers your query.