Answer:
Old people and owls are said to be this.
It makes me warm and secure.
This is a plant named after a light source. What is it?
I'm a god, a planet, and measurer of heat. Who am I?
Though I should be unique, you've made most of us the same. I would be stronger, if my characters were stranger.
People take me on walks and I run and have fun. What am I?