The third item you showed in the fishing kit is a spear point. Put it on the end of a stick then spear the fish and pull in with the line. The large barb on the point holds in the fish, just like a small harpoon. I really enjoy you videos, something about you is easy to like.
I think the black thing is an attachement to fit on a pole, so you can spear fish and when you hit it will detach from the pole. But that is a guess so hope i'm right :D