As a Pens fan, from their roster they've got McCann and, if healthy, Nick Bjugstad who seem to fit the Oiler's needs.
Larsson isn't much of a need unless he can play both sides on defense and is an asset to the powerplay. Which I don't think he does either of those things.
Puljujarvi is certainly of interest to me, but his waiver status is concerning. I've got no clue what his value is given his situation.
Other names from Edmonton that I can see of interest to the Pens and that the Oilers may consider trading are: Athanasiou, Chiasson, Khaira, Klefbom, and Nurse.
You are 100% right. Larsson has no business on the PP and plays RHD exclusively.
The return for Nurse or Klefbom would have to be extremely high for Edmonton to consider moving either. Klef is their #1(really, a #2 on other teams) and is signed for three more years for cheap and Nurse is a #3 and has a good bridge deal.