Recent questions by our 4.5 yr old girl

1. Who is exactly God?
2. What happens to us when we are dead and why can't any one see us then?
3. Why do birds have to fly around for food and why do my story books show them working in the kitchens like us?
4. Why only some teachers are good?
5. What is that thing in water that puts the fire away?
6. Why do we need summer vacation? (!!)