i agree with most of the statements you made. The more I messed with the hitboxes, the more I realized how bad they were lol, leading to the many issues you stated, even the one where you can't hit several enemies at once. I tried to fix them several times, but I'm not sure how to without redoing the entire enemy and player scripts again.
And about spawning the co-workers from the end of the walls, i already tried doing that, but then they would just bunch up there until the players walks across the room. I programmed to spawn the co-workers randomly at 4 areas every 7-15 seconds or so. I'm also aware of there being more co-workers spawning than the counter says there is. All that counter is saying is how many you have to kill to be able to escape. I again tried to fix this, but didn't know how to.
Music was one of the things I wanted to add as well, but I couldn't find anything that fit with the game's style and aesthetic on time
Thanks for the extensive feedback though :)