Arguably no, since you can only torture a possum with a BB gun, not kill it.
Because the air pump in a bb gun makes the bb feel like a pinch
Yes if you get hit with one it will hurt
No
Yes
No.
YES!
Yes it could cause problems.
YES! Very much.
70 FPS is considered low for a bb gun, of course if you were shot with it it would still hurt.
Yes it does hurt to get shot by a BB gun, due to the hardness of the plastic pellets, and the speed they travel out of the BB gun. The effect only lasts 2 minutes depending on what type of BB gun was used.
Any gun can just as easily hurt its owner as anyone else. There are many companies who make BB guns that will last for years