I’d really rather avoid this. It would be a very poor game experience for guests when host disconnects because “the game is over for them”
That makes sense, however it still won’t fix cases where a zombie is ramming into an enemy but the keys are collected by another (alive) player.
Why would you need to know that?
Because you’ve selected “Darken other players”
Those two mean the same thing.
No. Too much work and will be ultimately circumventable. These things never work.
Changed in v.97 
Idea
I can’t really stop people being jerks. Next, people will complain about hoarding gifts and atoms.