I think lockpicks would be a great addition to the game.
They would be just as rare as keys and can unlock any of the colored locks on the basement door. As finding a single color of a key near the end game is a pain..
Now to make this not too overpowered, to unlock one of the locks you'd have to play a small mini-game to pick the lock, (I,e Skyrim)
It would also play a soundcue Loud enough for the neighbor to hear, giving him a chance to head to the basement door while the player is distracted.
This would make lockpicks be a risk reward item, players having to risk it to see if they can pick the lock in time before the neighbor finds them