They were never errata'd to have the Pilot (x) keyword (see the FAQ for official errata, though the image posted does have the correct text). However, their post-errata text allows them to function very similar to units with the Pilot (x) keyword.
For your specific questions:
-Stay on Target can bring them in because they are Pilots (which is a Trait and not a Keyword).
-They do not have a pilot cost.
-Their text allows them to enter play as an enhancement, which allows them to become an enhancement when the Falcon puts them into play (pre-errata you could not do this).
-Luke and Wedge may only enter play as Enhancements if on a Speeder of Fighter. Luke cannot (and never could) be attached to the Falcon and then become a unit from bouncing the Falcon.
Corner case: Stay on Target can attach Luke, Wedge, or ever Rookie Pilot as an enhancement to any vehicle. However, Rookie Pilot (or Luke/Wedge if not on a Speeder or Fighter) will be immediately discarded in that case because Enhancements need continuous legal permission to be attached to other cards and their text does not allow them to be attached in that case (this is the same reason that Tarkin causes enhancements to be discarded when blanked).