Just picked up this thread now.

Regarding Istanbul: when I arrived there on LX I got a fast lane voucher on board the plane and went straight to the fast lane immigration. Same on LH. And IIRC also on TK. So maybe it's just a case of AF not handing out fast lane vouchers.

Regarding USA and arrivals in P as well as HON on LH: I am not sure if AF First Class can cut the lines with the personal assistant at LAX. It works at JFK for sure. As for HONs, it is not only LH but also LX and OS. But not for their FIrst Class passengers. However, that service does not work in LAX.

Other than that, off the top of my head, where fast lane exists at departure for SkyPriority:

Zurich
Dusseldorf
Dublin (only for business class pax, not elite pax in Eco or PE)
Most US airports for domestic departures on DL
Doha
Mexico
Glasgow (?)
Edinburgh (?)

Where it does not exist (again, off the top of my head and things may have changed since):

Geneva
Barcelona
Munich
Frankfurt
Hamburg
Beirut
Madrid (?)
Riyadh
Jeddah
Dubai
La Rochelle
Biarritz
Nuremberg
Verona
Florence
Stuttgart (?)
London LCY