Now that you point out those possibilities and after working a bit with the footage, I do believe you are right. It may very well be that I will cut out Tarkin completely, or rather just as much as possible.
I won't cut out the the tracking beacon simply because it's a much easier way of showing how the empire finds the base, keeping it simple will help cut down the runtime. However, I do like the idea of introducing Boba Fett earlier in the film and I'll try and see if I can work him in some other way. Also, on the point of Boba Fett, I will try and make his death in ROTJ a little less ridiculous. I haven't given it too much thought, but I was thinking of possibly having the blaster shot that Luke deflects hit him, and that's what activates the jet pack and sends him over, or if I can find a way, I would love for Han to be the one to kill him, just in a less stupid way. I'll let you know when I figure out what to do with that particular scene.
I am still planning on Luke having two trips to Dagobah as I feel Yoda's death is a real important factor in the story and can't find a good way of putting it in before Luke leaves for Bespin because I want to keep it so that Luke disobeys Yoda's advice in Empire.
The Battle of Yavin will not occur in this film. There will only ever be one death star in this. It will be destroyed at the end of the film by Lando and the rebellion. If you missed it, this was explained in the first post of this thread. =) Thanks for the interest.