Originally Posted by Pedi Dustyboots
I haven’t been to Deadmines myself personally
No, no danger at all. If you go to Deadmines and beat it and then go to the NPC, you’ll find that you’ve only wasted time because the NPC won’t recognize what you’ve done. You only get credit for the kills once you activate the quest. So that means, you’d have to go back to the Deadmines and do it all over again. Same thing for quest drops. You can kill mobs all day long, but you won’t get the special quest drops unless the quest has been activated for you. It is not like you can gather components ahead of time and just have it ready when you go up to the NPC. (Some quests will ask for common drops off mobs like leather or animal meat so these are the exceptions, but they are far and few in between.)