I think it is possible haraldo23.
But you are right. It will require a lot of time and money to create a professional and seamless blend.
Set dressing, costumes, lighting, camera lenses, sequencing, direction, acting.... and a million other things.
It will be quite the under taking. However, if you look at these edits they are increasing in ability each time.
ANH:R was just computer editing with 2D objects. ESB:R will have the first sequences filmed and models built. ROTJ:R is the next step into full blown filmed action sequences.
Matticon