What Am I Riddles

Question: I do good things, but one small push could be a horrid disaster! I am normally used for decoration now.

Question: I rule the ends of the universe. I control its laws. I reign the galaxy. The start of space is the start of me. The end of the universe is the end of me. The name of my slaves bring mighty terror to you. The universe wouldn't work if it wasn't for me. What am I?

Question: The more you cut into me the bigger I grow, what am I?

Question: I have no wallet but I pay my way.I travel the world but in the corner I stay.

What am I?

Question: Take my first and make it my last, now I happened in the past.

What am I?