Actually, with the power of Atlantis activated, which made it so that everyone's desires would come true, Van too can go see Hitomi whenever he wants. As for Hitomi's pendant, it's more of a symbol of the dependency she had on fortune telling throughout the show. And as she became a stronger person, she no longer needed it. It was only right that she would give it to Van as it is both a gift and a statement that she has become a different person from the insecure girl she was at the beginning.
The ending? The girl had a home to go back to. She has a family and friends over there. Leave her alone. She did the right thing coming back.