You have limits, and finite paths to take. You still have to have your life, while giving your child the best chance to succeed.
I'm having my first boy now, and I intend to show him as many different fun things to do as possible, and the sciences involved in performance around those hobbies.
I.E. RC flight, so that he may learn some hand eye cordination, and get a lesson on aerodynamics, thrust to weight, stall speed, pitch vs. diameter, etc... in more arbitrary terms like better battery, smaller prop, etc..If he is interested, he'll want to know "why" does a smaller prop work better for speed, but not thrust.
What the tradeoffs are for a bigger heavier battery can be illustrated in a more scientific manner. Then we can show him how to do that work when he's curious as to how these things relate to his hobby.
I say give him the options, show him the laws of economy as it relates to the choices in his life. You can have anything you want, but can only pick it's qualities from 20 pts in this scale:
Good(10), Fast(10), Cheap(10) (or the variants as situation deems necessary).
Don't try to influence him w/ your prejudices (which you will do just by a slight twitch in the eye anyway). But instead explain how people who spend time doing this activity increase their abillity to do this while decreasing their abillity to do that.
If he wants to do Ballet, we're O.K. w/ that too. And as he wants to do better, we can help him by showing how form takes strength, self control & discipline. How a story can be told w/ the motions of the body, etc.. (It's not for me, but were he to so choose, I say smart kid, great way to meet lots of girls...)
I hope it'll be the "right way" for our son, and I hope I can stick to this plan.