Ahhhhhhh yes! center-mount them at true center for sure. I did the same thing on my AR6s and they're definitely the best park ski I've ever owned. As your inquiry about the reason the pros rock their mountings at like -1 or -2, that's just their preference. To be completely honest, it really doesn't make that big of a difference. Dramatic differences between various types of mountings or differences in mountings on pow skis actually can make a big difference, but when it comes to park riding anything around center will pretty much ski the same. Personally, though, I like the true-centermount for a couple of reasons. First, best possible ride switch. Ya, a few inches don't make that noticable of a difference, but they do make some difference and why not take advantage of that. Secondly, best swing weight. Thirdly, being as far foward on your ski as possible will give you a pretty aggressive stance which is a form of riding that I personally like the best. Finally, who doesn't like the huge-ass tails that centermounting gives you? it looks dope. On another note, centermounting also wont really hurt you on moguls, groomers, packed pow, etc., contrary to popular belief. If you have the ability to shred that terrain, you'll be able to shred it fine and the more aggressive stance actually, imo, makes it more fun.
Also, forgot to mention, that far foward gives the ski the maximum buttering capabilities, which can make riding anywhere, from the park to the moguls, fun. So, do it, tell your shop you want the boot mounted between the ARM and the ADA on the side wall and you will have an awesome ski at true center.
