Yup, But you need to be extra careful. Use perfect form. Once it has muscle on it, then start going heavy, but still be careful.
Yes, it will prevent you from having a bad back in life. Never crack your back, only stretching is ok. Twist side to side and hold it, dont twist so much that it cracks, that makes it weak.
Goodmornings anf hyper extentions are really good. Same with deads and squats.