Can I use Jyn Odan's Quick Draw if I don't have line of sight normally, but do with Trick Shot?
Yes

Justin Kemppainen, Assistant Board Game Manager for Fantasy Flight Games, definitively stated that it is allowed:


  Question:
  If a Trooper "just around the corner" (out of LOS) activates, can Jyn activate Quick Draw and Trick Shot (to gain LOS) to attack him?
  
  Answer:
  Yep! That combination of abilities is legit, and they remain legit even if the target is not currently in line of sight.