The best part about music is that you can ask 10 people and get 10 different answers. If we all agreed, it would be a short boring conversation
As for sharing lics, that's a blues/jazz thing. Those guys always shared. Check out the real book. Or when people talk about "standards". These are songs someone wrote, but have been played so many times by so many people they are just sorta pulbic domain. The blues guys aren't worried so much about who wrote what, they want to play!
