I finally watched --Great summary, thank you!
Regarding #3 - Sonic workers knew KK came in with PF to get coffee.
This is the part in Dateline that is built up by narrator as investigators coming to Sonic inquiring about "the blonde girl" and/or who's the "mystery blond?" I agree the
mystery blond girl here refers to KK.
Just to clarify, seeing several posts asking "what blond girl?" or "who's the blond?" being answered as "blond girl is KB's cousin, Jody G." Yes, KB cousin is blond, and also appears in Episode but she wasn't the
mystery blond narrator referring to.
#4 PF put gas and oil into the plastic tote.
From the AA, PF put the black plastic tote, gas and oil inside a 100 gallon trough. I don't recall it ever stated or written that PF opened the tote in front of KK, or that PF put gas and oil inside the tote. Eeeek, where did that come from?