this.
If they argue, just ask them if they are saying you can't follow your dreams. If they say yes, peace the scene. You sound far too sheltered for your age man. I knew kids like you in high school, and I know people like you now, as a 20 year old in university. Just letting you know, all of the people who chose not to express independence and "break free" are still living the same sheltered livestyle now as they did back then. Do you want to live with your parents and let them make your decisions for the rest of your life or do you want to be your own man?
It sounds like satisfying your parents is very important to you. I can relate, I'm in engineering school and my dad is a chinese dentist who's paying for my education. But, remember this - in the end, your parents care about your well-being more than anything, at least they should if they are decent parents. If skiing park makes you happy and you love it, then express that. It would be pretty cold for them to cut you down for that. If you wanted to start motorcycle racing or something... that would be different because it is a major threat to your life. Skiing park as opposed to normal runs with your family does not have that element.
No matter what, you will have conflicts with your parents. It's part of life buddy, get used to it. Sometimes there is a necessary struggle to get what you desire. There is a reason why we all (well, most of us) feel the need to move out of the house eventually. I'm not saying that you will have a bad relationship with your family. Family will always be a part of your life, but that's the important bit - PART of your life, not YOUR LIFE.
But, if you would rather not make your own decisions and do only what your parents tell you to do, rather than having your own life, go right ahead and continue what you're doing!
fuck I wrote a lot, hope this isn't a troll...