Trust me, getting zapped by the boss is NOT uncommon.
The rumble pack is something you can get by collecting gold skulltulas. You need to go to the skulltula house in kakariko village. It's one of the rewards you'll get for collecting a certain amount of skulltulas. Don't pay attention to the...
Barinade can be a pain in the ass but if you know his moves he's actually easy. As soon as you start try to hit the tendons and take them out. Then he starts to swing around. Because the spawn is wide you can get closer to him and stun his lower body with the boomerang. Then hit him. He starts...