logbook for pilot hours and "what you claim on your airline app" indeed may be different. PIC for airline app purposes is "Aircraft Commander, Captain, final signor, final the crap-stops-here person in charge of the plane." For this purpose, the guy may not even TOUCH the controls but if he is responsible ultimately, for the safety and success of the flight, he is PIC. PIC is about RESPONSIBILITY, not yoke-holding, for airline app purposes. Yes, he must be legally qualified for that airplane.

I think of PIC as "PRIMARY in command" and SIC as, surprise, it is SECOND in command.

If it is a two seat airplane, and between the two of you, the guy PRIMARY in command is the PIC. Period, the end.

The King Air stuff is indeed a grey area. A King Air 90 is one thing, the type rating required B-350 is a little different. tread carefully and be able to articulate what you "claim" when you apply for jobs.

my two cents