I absolutely love the boldness of this idea. I wish it could work, but I don't think it can. Presumably you still want a climax to each movie, despite the "saga" idea. Well, without the destruction of DS1, ANH doesn't have one.

You'd have to cut it off after they rescue Princess Leia and they move to Hoth because they find the tracking device on board the Falcon? No, wait - there is no Yavin base, they escape with Leia en route to Hoth - end of movie. Then the battle of Yavin is used at the end of ROTJ?