Totally fair and I do appreciate it. It is absolutely complex in unusual ways, and you were on the right track. There's alot happening in the background.
The easiest way to explain trace is that "The more it fills, the closer the boss will the spawn enemies" and not try to fully understand it. At low stages the boss will spawn enemy tiles randomly across all the floors, but as it fills it'll narrow down towards your current location, down to the specific tile you are on. By moving to a new floor, it loses track of where you are and spreads out the attacks again.
"Peer" is just the camera enemy's attack ability, that increases Trace. So, some enemies attack you directly, while others send data back to the AI to either track you down or allow it to gain its own growth XP. So, there are lots of minigames are happening all over the place so I totally understand the confusion.
I'm not sure what would have killed you on the 4th floor like that, but I'll have to take a gander. I do appreciate you giving it the college try.