Answer:
I can be short and sometimes hot. When displayed I'm never cold. What am I?
I am heavy forward but backward I am not. What am I?
I've been argued on my color. Without me you'll die. So many attempts on your life use me so make sure you have many of my White friends.
The more holes you cover the lower I go.
I go through a door but never go in and never come out.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.