The rattling latch thing makes so much sense. I had something sort of like that with a gate, not the coop itself. My girls were fine in the boxes but they quit going out to the yard for like two weeks and I could not figure out why. Turned out the hinge on the back gate had rusted and it made this high squeak every time it moved, even a little. Drove them nuts. I oiled it one afternoon and by the next morning they were scratching around like nothing happened. It is wild how much a tiny sound bothers them when we barely even notice it. On a side note your post made me think about how my old rooster used to do this low grumble whenever a plane flew over. None of the hens cared about planes, but if a hawk called from the treeline they all froze. Those birds hear stuff we flat out miss. Good catch on the duct tape, cheap fix for a big problem.

I read a thread on a contractor forum where a guy said he prints out every 1 star review and tapes them inside his truck. Said it kept him humble and he stopped losing repeat customers. That stuck with me because arguing in the replies does nothing except make the next person reading it trust you less, lol. Fixing the thing they complained about is the only reply that actually counts.