In my opionion, if you desire to become a tech and eventually run the business, that is what you should focus on. It sounds to me like you are passionate about this profession.
I agree that you are right on track about running the business more so that working in it. Keep getting as much information as you can about managing and marketing your dad's automotive shop. This website a great resource for answers to all your questions...THANK GUYS!
There are several automotive management and automotive marketing companies that will be helpful in running and marketing your business. I hope it's ok to name of few, I'm not trying to sell any of them but just listing the resources that I know of. There is ATI, Management Success, Cinron, Dan Cricks, Autoprofitspro. These are just a few that I have heard about, but again, this website is especially helpful because your questions are answered by people that are in the same field. And, it's great input and advice on what has/is working for them and what hasn't.
Good luck!