Having just turned 14 two weeks ago, I regularly ski by myself on vacations out west/to Europe on 40+ degree stuff and 10-15 foot drops.
I feel that as far as cliffs go, 20-25 should be max or else serious injury could be involved. And steeps, 50 degree max or else you could fall down the entire slope in a fall.
So I was in Kitzbuhel skiing this gladed 40-45 degree chute with fresh tracks to the side of the Barenbodkogel chair with a friend. He's busy joking around when I'm serious as any fall besides a light fall (just losing balance and having your hip hit the upper slope) would result in a nasty fall. And such, I feel that he is putting himself in danger by skiing steep, narrow terrain with a few trees and fooling around. So I say, "_____, get serious! I'm pretty sure a fall would hurt." Dumbassly, he says "yeaaa... sure...." and on the next turn while supposedly saying (as he interprets of the story) "So after skiing we will..." and skis cross, falls down, skis go under the meter freshies and falls just 50 ft down the slope and 10 ft in front of a tree. Nice one.
And I'm not saying all kids are ignorant idiots. Just that, well, what I learned was that skiing with friends that you know won't get serious in major situations like this are not the ones to put your kid skiing alone with. This resulted me in skiing all the extreme stuff by myself for the rest of the week, as he would chicken out and I wouldn't want him getting hurt and/or distracting ME. He clearly did not also know the dangers of skiing a steep slope as such, even though he claimed beforehand to say "Let's do this!" (He is also a better boarder than skier, and this was the one of two days in the week that he skied and he could have easily tackled this on board)
So what I think is it depends on how you're kid is doing. I know a danger of falling, but does your kid? Steep results in big falls. Big falls result in injury. And if you haven't figured it out, injury is not good.
And I should have never been allowed to do this last year. When I was 12, I headed into Mott Canyon @ Heavenly with my sister (during the period of 3 weeks with no snowfall). First time really skiing out west (JH as a lower intermediate doesn't really count... that was also 5 years beforehand). First real steep skiing (steepest beforehand was about high 30 degrees pitches, but Mott Canyon is 37 degrees over 1k vertical about).I had never seen steeper. Like the fall line escaped before me. Anyways, me and my sister attack the line under the lift. We didn't fall once. Felt great to be skiing our first sense of steep. But then we tried more on the ridge to skier's left of the canyon. Here, a 4-5 ft cornice developed. Somehow, our first cornice was dropped with just a minor fall by both of us onto our sides. Hugh. But then on that first turn, my sister messed up, and fell 200 something feet down the slope. Mott Canyon has trees and rocks and other dangerous hazards. She was okay, except with a small cut on her thumb from trying to stop herself. Another skier quickly skied over to her to see if she was OK. She was okay, but that was the scariest thing that happened. That was the realization that bad things happen out there. She was lucky she didn't break anything, or hit a tree and suffer a concussion or worse.
Now, so it depends on exactly how your kid is. He should understand the danger of having a fall on steep terrain. I would have definitely been more careful if I knew that falling in Motts would be this bad and same with my friend in Kitz. On the east coast, a fall is a fall. On 40 degree double black slopes, a fall isn't good. And the steeper, the deadlier.
And to fully grasp this understandment, I'd say what I said in the start.
Oh, and question: How old is the youngest person to ski Corbets?