Does Goku get back to his normal size in Dragon ball GT?

Answer 1

You don't actually see him "directly." Basically he disappears at the end and the episode ends with his "great great? grandson..." who looks just like him being trained by Pan (who is now his grandmother). She tells him about how Goku was the greatest fighter in the universe. There's a scene where Goku, in his grown up form talks to the young Goku (the great great grandson). Then disappears again. So yeah he grows up to his normal size, but not instantly by the power of the dragonballs or anything. He just grows up normally again.