I think you have to buy the pack once in order to remove the lock from blank cards and see the odds. Dangers in the dark need cards from "Danger Zone" pack. For feeding the world I have no idea, I also have the last card locked.
I've determined what unlocks the Danger Zone pack: Unlocking Resin in Mining.
When/how does that happen
Just gotta reach certain depth. I think it's around 160-170, I don't remember exactly.
