1. No. You might say "Boy, you're exactly the same Julie as you were before" if you want to stay close to your formation. But the most natural way to express the sentiment is simply "You know, you haven't changed a bit."
2. Imagine you haven't seen a friend in a decade, and you bump into her. As you're having a chat with her, you realize she hasn't changed at all.
Really the most important thing is to be consistent with tense. Your original sentence mixed past and present ("You bumped into a friend....you feel she hasn't changed..."
You can use either tense; you could equally well change your original passage to "Imagine you bumped into a friend after not having seen her for a decade. After having a chat with her, you felt she hadn't changed a bit