Paraffin wax is a petroleum, coal or oil-shale derivative that is white or colorless and a soft solid. It's used in candles, crayons, as lubrication, and electrical insulation.
You should, but if you have sensitive skin, you can reduce this time to ten minutes. If it doesn't remove the hair though, you may need to leave it on...
No, it's not necessarily bad. You just want to make sure that you're super careful. You don't want to accidentally rip a chunk out of your eyebrows that you didn't...