CTM,
Your theory is fine.
If you want positive feedback in your posts, I highly recommend the use of paragraph breaks and punctuation. Otherwise people won't pay attention to what you're saying and they will flame you out of hand.
We know there will be multiple villians. I am guessing that we will have four or so main worlds with a Sith Lord on each, much like we had with the Star Forges. I also suspect you can do these in any order again.
If your theory is correct, Yavin IV may be the place to end the game. Imagine a final showdown with Exar Kun's force ghost.