I'd be down to record a gameplay video and upload it as unlisted to show you generally how I approach the game and the sort of loops I did around the camp if you'd like to see how a player moves through the game.

1: I did get stuck near the church! There was also another building that had deep cliffs beside it, I think it was just a building of some kind (house?) but not a church? There was also an area next to the greenhouse that I got stuck, but I don't remember if it was front or back anymore. It was around one of the corners, I think towards the cliff/open area without trees.

2: Around 45minutes, most of it was wandering and some instances where I would do something (there's a cabin with a light switch at the back; I struggled seeing if I could turn something on there, but decided I likely needed the 2 staff chips (to power the tower) that I couldn't find to get the cabin working or see what the switch was about, so I moved on).

3: What would have helped sort of depends on the kind of experience you want users to have. If they should be quick to get items to solve puzzles to solve the level, items should have some kind of light ring around them when you are close - because they are easily missed in the darkness. If the game is meant to take as long as it takes until you find the items, perhaps a map that indicates where items may still remain, a way to ping for the *general* location of remaining items, etc. I think having text indicators when interacting with an object that needs a piece still would be good; i.e. when trying to interact with a door, if there's no interaction, you won't be able to get in. If you interact with a door and it says "There must be a way to open this" or "I think I need a key for this door" it's a good indicator that there's something to do.

Players are intended to solve a mystery so I feel the game can be approached with that kind of mindset - so with that in mind, you want players to pick up items and have them feel like they have solved a puzzle when it comes to things like doors and keys or puzzles on the map. Maybe there's a room with a single light inside and a key glowing on a table nearby; from the inside there's no door you can open that gets inside, but maybe you can fall through broken boards in the ceiling above and then unlock the door from the inside. The reward and payoff in that situation is players recognizing their environment is weird and seeking out the "Answer", and being rewarded with something that helps them elsewhere to progress the game.
I feel like this approach is sort of being taken with the game, but it feels a little disjointed because you are just left to wander in loops around the map.