First off... absolutely GORGEOUS song... thanks for introducing me to such a wonderful artist.
Now, about the video... I think there are some good scene selections but the sync feels a bit awkward sometimes - I would recommend using crossfades for this particular song because it's a very soft song; straight cuts feel too abrupt for the feel of the video.
Video quality is my second complaint; not sure where you got your copy of Nausicaa but I know the remastered DVD release of this anime looks a lot cleaner than that. There's a lot of pixelation and blurry frames in your video - I would turn off re-sampling and de-interlace in the editing software for this source because it feels to me like the editing software is mistreating the footage.