I passed all the quests from the mechanic to assemble weapons and only after that, having level 50, I got the first quest on lightkeeper. At the same time, the pest control quest was not completed for me and opened only after killing the boss at the forest location by the quality of the hunter's path.
Just completed all my gunsmith tasks. Ill let you know what level I am when I get lightkeeper unlocked, as I am still trying to complete the required quests given by the wiki. I guess i got to hunt shturman.