Watch someone involved in TREE CARE. In TX, asphlunde does utility work. That means they care for power lines, not trees. Their focus is to not have 100000volts hit them. Trees are way down the line.
I think they get a tax break for employing ex-cons. You might be better off facing brian with his 260lb chainsaw swinging groundman. Many of their crews are just plain scary.
You should work with at least a few different tree companies. Climbing methods and business types vary greatly. You seem pretty keen so you will learn fast. You will also learn to climb fast and efficient as the slowest guy is stuck dragging brush. Do it, even if you think you are too smart for ground work. Coming from academia, I had a hard time gaining respect from other arboristas when I started in the field of urban tree care. respect is earned from logging in hours in the saddle, on the ground, and yes, believeing in yourself.
Nate
ps - Sorry if I offended any utility personnel. I have a great respect for their bravery. My life is too short for that work.