Will my client benefit the most from the next session of deep subconscious channeling to work on his marijuana use, or his effort to get a job to advance his career?

You are correct in leaning towards the former rather than the latter. It is not a harmless recreation or self-indulgence to help him tone down his concerns and be less stressed and anxious in worrying about his career getting going. It, indeed, is undermining him in multiple ways, most particularly his continued vulnerability to the targeting sent his way. Indeed, it is safe to say he will never advance as long as he is making himself so very vulnerable in this fashion. He has no idea what he is up against. He needs every bit of inner strength and resolve to stand up to the slings and arrows sent his way. It will help deal with the karmic underpinnings in turning to this self-soothing strategy. But, as you know, there are no guarantees because of the self-reinforcing nature of drug use. It is very difficult for people to let go of, as a crutch to help them through their difficult days.