Answer:
I am a type of weapon for SCI-FI characters
Marking mortal privation when firmly in place. An enduring summation inscribed in my face.
What has 4 fingers and a thumb but isn't alive?
A hole in a pole. Though I fill a hole in white I'm used more by the day and less by the night
A girl who was just learning to drive went down a one-way street in the wrong direction but wasn't stopped by police. Why?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.