If you know the kid well I would let him work as long as he is supervised.

What stops me is that I don't have time to supervise a crew, run back and forth to home depot and other related tasks that my Contractor does.

Especially if you are going to need a large portion of his time for supervision.

Use a builder that you trust and will not require your supervision on a daily basis. 

They should be able to supervise light to full rehabs + all the basic jobs that a property manager does.

I would start with free, unbiased education and move along toward actual practice as an agent or salesperson under the supervision and guidance of someone local who is willing to train you and answer questions, learn about the RE laws of your state, become familiar with your market, see how comfortable are you speaking to strangers and build relationships; the rest is up to you. 

If he gives you even one smidge of hassle, contact his supervising broker immediately. 

I plan on going after 20 units and under initially so I can easily manage and supervise the renovations.

,successful out of town flipping requires two important people,a trust worthy general contractor to do the work on time and without supervision and a real estate agent who can sell the property as well as monitor the construction phase every few days to double check the quality and completion of the work.You need to establish your "Power Team" before you go looking for properties so everything goes smoothly from beginning to end.

If you didn't supervise work done or visit the property once it was deemed ready to rent, I would find another property mgmt company.