I do not know how they ride switch as I just received my Alpha-1's in the mail today, but judging from the numbers of product videos I've seen, I'm sure it wouldn't be anything for you to really worry about. I've been eyeballing and studying these skis for nearly a year so if there's anything else you wanna know feel free to ask me!
No, they are not symmetrical. Mounting them center doesn't sound like a good idea; if they wanted you to center mount it, wouldn't they have made the ski symmetrical in the first place? The factory recommended point for mounting them is at -2.5cm from pure center. No worries, man.
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Also, I'm really not trying to thread-jack you here, but I'm 16, 5' 6", a type III all mountain skier on the West coast, and I'm a beginner/intermediate to park skiing but I've taken a proper 3 day camp to get down the fundamentals and principles of park skiing. I plan on dedicating my whole season to park skiing and working out to be in top physical condition. I purchased the 176 cm Alpha-1 but do not plan on mounting it until very late in the season and have the confidence to say that I am an advanced park skier. Was this a good choice or should I have gotten the 170's instead? I'm not going to buy another ski for about 2 years, so that gives me plenty of time to grow into them.