dear god please dont tell me you could lock your self out of specific parts of this game just by losing a singular item and have entire activitys be cut of from you. ok another question can you put the unattached hook-end, that you can find outside to the other end of the half hook, i lost the hook end and the EMF reader do to a explosion that i didn't even know that would happen, or even effect them so hard. now i cant even find them because they went out the top of the garage, with no way to find them and having potentially locked my self out of aspects of the game. please tell me there are other spots that you can find these, or that you cant attach anything to the other side of the half hook, or that the EMF reader doesn't do anything to useful. god im so done.

I can't give you a certain yes on that, but I think it is possible to soft lock yourself out of certain events.

However, those are mostly easter egg kind of events that are not story relevant, see it more of a bonus content that you missed that might not even be canonical to be in the game to begin with.
Like, let's say you lose one of the Metal Tiles forever, you won't be able to do "a thing", but that thing is not relevant in any shape or form anyway.

There are a few more things that you can permanently miss, but those have no impact on whether you can do something or something happens or not, so don't worry too much about it.

Also, there are many other things that can be missed, so several playthroughs through the Story Mode to see them are not too uncommon of a thing to do. (or play the Infinity Mode which itself also disables certain things)

if you lose essential/unique items, you can make a new story mode save to fetch them, and put them in the mailbox. When you save, the mailbox is saved to a different file that can be access by any other story mode mailbox, so anything that fits in your inventory can be sent between saves as needed. As for missing events and specific items... don't beat yourself up too much or stress about it, there is A LOT of minor events in the game and you will miss easily half of them to random chance alone. It makes playing through the game when it updates less boring and predictable