Why do multi-engine turbines start the number 2 engine first?
I don't believe that would be true for all multi engine a/c. Usually the first engine to be started would be the one with the hydraulic pump that supplied primary brake pressure.
What are the fins (vanes or strakes?) on the inside portion of the engine pods on most jet transports?
Called chines they are there to improve the airflow around the wing and they improve the stall margin by typically 5knots.