First of all, if Frankie was a medical student like he said, he would have known that you DON'T DO CPR ON A COUCH! You do it on a hard surface. It seems they were having sex on the floor, so why would he move her to the couch to do CPR, when, as someone in the medical field, he'd know better?? (Unless they were on the couch doing some post-sex cuddling by then...)
If Pheobe died and Cora disappeared for two months, why wasn't there a publicised, massive search for them? Is the skeleton at the school bus going to be Pheobe? Her parents talked about her dying, though, so how was her death explained to them?
Personally, I think that was a LOT of sex and drugs for a sick teenager who's never been around peers before.
The scene where she's talking to her sister outside the bar, but we'd already seen it as Cora talking to the other girlfriend... That was a trip! It did make more sense with the conversation being between Cora and Pheobe, IMO.
All in all, a very trippy, not-sure-what-I-should-believe episode. Although I was happy enough not to see Ambrose or that skeleton-face lady detective they brought in to be over him.