A: Your fingers, I have used a drum stick, one friend uses his leather wallet. Q: No, the tuning is by tentioning the string. You can fret once to get a higher register.
A: A good two octaves.
Q: How loud is it?
A: Very <98dB.
Q: How long does the string last?
A: Indefinitely unless it gets damaged by something or someone.
Q: How strong is it?
A: Very, you can sit on the side and put whatever you need inside.
Q: Can you play pool with the cue? A: Yes!!!