I've been playing for a few days and have some questions about events that happened to me.

When I first started the game, I came to the base, processed some signals and wanted to sleep, but couldn't because of some event. I sat on the bed and was scared about what could be outside. (Also, I've seen someone on the radar to the northeast.)
After a while, I managed to sleep, and when I came out, some furniture was moved, and the table in the break room was missing. What was that? I haven't found any events related to this.
I was upset that the furniture had been moved and was kinda scared it happened on the first day, so I started a new game.
Around day 10–14, I came into the kitchen upstairs and was about to use the microwave, when all of a sudden—BOOM—something exploded in the hallway and threw me away. (It was so unexpected I got goosebumps.) I wasn't hurt, but all my small stuff was scattered around the room. Same in the garage, upstairs storage, and main room. What was that? I tried to find the source of the explosion or some relevant event, but found nothing. Was it a bug?
And also, what is that sign? I saw it from the northern windmill (photo).

And also, what is that sign? I saw it from the northern windmill (photo).

It's just an easter egg, don't pay attention.

Deer may be displayed on the radar, so you shouldn't panic too much from every dot either.

As for the rest, it's hard to understand what could have caused the explosion. But there are a couple of loud events that can turn everything upside down at the base. One event happens according to the story on a certain day (I won't say when exactly, I don't know). And the second happens when you catch a certain signal and is accompanied by a blue light and a rumble. Both events eventually leave stationary dots on the radar and you can go there.