Whew, I had to read that several times.
But, as I understand it (which is tenuously, at best :-), that wouldn't work, because the assumption that space is fixed and matter is moving around in it is now guessed to be wrong. The latest theory I know of is that space itself is expanding, which means that the lines you used to figure out where/when you want to go would be curved.
Also, there's no guarantee that "until where you want to be is where you are" will ever be true - maybe the point I want was never on the time line with where I am.
Then again, if you could go back to the big bang, when everything was close together, then it's a short distance from here to the other side of the galaxy. But living conditions were not quite right.
Anyway, it's time to say good night, Gracie.
;->