Yes.
That depends. What mining equipment do you have in your rig right now?
Because it runs on electronic equipment, and electronic equipment requires electricity.
No.
To answer your question about how much electricity mining uses...
Lets assume you've purchased and set up an AntMiner S5+
That should get you about 7,722,000,000,000 hashes per second and will draw about 3,436 watts.
With 7,722,000,000,000 hash/sec it will take you about 1010.4 hours to generate 1 BTC.
3,436 watts for 1010.4 hours is about 3471.7 kWh of electricity.
If you pay $0.15 per kWh (including all taxes and fees), then it will cost you about $520.76 to mine that 1 BTC. Of course you could have just bought it for $420 today instead of paying $520.76 for it (plus the purchase of the equipment) and waiting 6 weeks for it. Depending on where you are running the equipment, you might have to pay additional electricity costs to run cooling equipment as well (to prevent it from overheating).
Thanks so much man! You really cleared my head on this one