The only profession that uses parkour directly is coaching.
Oh Dave, if only life could be so simple that all of your answers could be "right". The reason people argue with you so much is that there is ALWAYS more than one side to a story, and many answers will have elements of being correct.
There are lots of careers that could use parkour directly any have been listed. There are people who use parkour and freerunning to do performances and do that as a near full time job. There are people who have very good and active stunt careers and they use parkour very directly in their work.