The ending...
Did they become stars at the end?
The candle Just could help them travel fast, and could not cause transformation. So I suppose they just traveled to that stars. then why they did not go to the same star?
They had just one candle and at last scene we see them disappear together. So they just could go to the place where they both had thought of that, not different places in the sky.
And finally I think if the movie wanted to show they still live happily, would be better to put them much closer. Because if I'm not wrong, when we see two stars from the earth with that that space between them, their distance must be too much. Even their distance would be much more than that if our angle and position of view to that stars be inappropriate.