Answer:
I am a fire's best friend. When fat, my body fills with wind. When pushed to thin, through my nose I blow. Then you can watch the embers glow.
I'm sometimes white and always wrong. I can break a heart and hurt the strong. I can build love or tear it down. I can make a smile or bring a frown.
I have split the one into five. I am the circle that few will spy. I am the path that breaks and gives. I am the bow no man may bend.
Describes universities like Harvard and can be poisonous.
At night I come without being fetched. By day I am lost without being stolen.
People take me on walks and I run and have fun. What am I?