Good advice so far. Brendon's and Bounce's schedule, where someone else provided some dependable income PT, and their own gigs PT seem like great ways to go when you have the skills developed already. I chose to go on my own with little experience with skilled residential arboriculture or climbing, and have had to learn on the job. Add to that learning to run a business. A hard way to start.
I, too, have recently started networking with another company. I've traded work, and contract climbed for him. I will need help when my employee leaves for Christmas vacation before I do. If my employee is hurt or sick or has a college obligation, I'm stuck unless I have a plan B and maybe C. Recently I used a temp agency for a guy for the afternoon on two jobs where I just needed an extra set of hands for a few minutes here and there to handle some brush coming down near the house, then some raking and brush dragging. They handle W/C, payroll, unemployment in their fee. The guy was OK enough, and I got rigged down what needed to be done. At the end of the day he was done, and I didn't risk an uninsured injury or fines from a broke state gov't working in the state capital by having an under the table worker. Don't know if LA is more laid back.
I think that you may want to handle your situation with your boss by renegotiating your arrangement. Maybe you could address your availability and status as an regular employee or legitimate subcontractor. You are paying your own insurance already. You can decide if you want WC. You might want to subcontract him if you get jobs where you need material handling and disposal on a larger scale than you want to handle, as I'll imagine he has more infrastructure.
Good on you for striking out on your own!