Hi! To answer your questions:
while flame is generally something scary, underwater I suppose it would be quickly extinguished by, well, water. On the other hand, a sudden and unexpected current of water while journeying under the sea could be a sign of something dangerous.
I had never really wondered about it, but my brain tells me that the answer is "in my fingernails". The amount of hope one can store in their fingernails is amazing, by the way, considering I keep mine short. It may be why my hopes are so sharp and well maintained, actually.
neither, I call ahead and then, since I'm expected, open the door without waiting once I'm here (or get the key that was stored in [specific place arranged beforehand] if nobody is home)
omg thank you so much, incredible answers right there!!! I am adding the vibe to the fic!!! <3