Hm......... well Yoda does tell Qui-Gon in the cut scene that he is now Qui-Gon's "student", so being lesser isn't an issue. If anything, you should find a clip from somewhere of Qui-Gon saying "of the Force" (shouldn't be too hard), so that it'd be "This planet is both an amplifier and a magnet of the Force". Then it'd be less confusing. Also, don't have "You must train Skywalker here" be after a fade out, it's awkward. Cut the fade to black and throw in another scenic shot of Dagobah, maybe from Empire.

Regarding the dialogue additions to the Star Destroyer scene... I think that the scene worked brilliantly without dialogue. It feels more forced with it. I like the idea of "Obi-Wan will die", just not there.