The only hard part of the final fight is the balance elemental, and that set up is fine for it. But, I have heard that if you range it you can get it stuck so that you only need to pray range or mage. I personally didn't know that at the time so I meleed it and didn't have a problem. I was 89 str, 85 att, and 85 defence when I did it, so with your stats it should be fairly easy. As for the tormented demon drops, no they can't drop anything during the quest. There is also a stone in the room that boosts your stats to 225(even your hp) for that part so you can kill them very fast and easy without eating.