also, I have an idea for how at least some of the inventory could work:
what if, for things like scopes, all three effects are active (but you start with only like 1 slot, so a passive upgrade could give you extra scope slots for more bonuses)
Due to how the game was written, this would be very difficult to implement and would take a lot of work, so I'm focusing on other content at the moment. These ideas are all super cool and inspiring though :)