I watched his edit, thats not even close to pretty average skiing. I'd like to see you post up an edit of your skiing, because there really aren't very many lines like that in any of the I- 70 resorts where you ski according to your profile. (I'm not saying its great, smooth your turns and ski the fall line dude! but its better skiing than most.)
15 din is definitely excessive for his weight but below 10 is too low for going big in harder conditions, especially when competing. I have prerelease multiple times on griffons set at 11 with proper forward pressure and I only weigh 10 pounds more than the OP. I do ski harder than most though. I have never had a problem with my skis releasing when they needed too at 12, even in the occasional low speed fall when fucking around or the two times when I caught a tip under a buried log.
Am I suggesting that most skiers set their dins above 10? No, but going big in harder conditions and going fast through bumps puts more stress on bindings than almost anything else in skiing including bigger park jumps, and the consequences of a prerelease are higher.
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OP did you compete in the Targhee junior freeskiing comp? I thought I saw a shot of peaked in your edit.