I think we should consider age as indicated by user's behavior (not influenced by their claims) with some more interest.
I've seen a recent increase in kids (clearly in middle school) getting hit with year-long suspensions (multiple suspensions of that duration, in some cases), both network-wide and on certain sites. Looking at how much kids I interact with change over such time spans, I think a whole year off is a bit too painful and it's likely to drive them away permanently, which shouldn't be our goal.
This is what I think our system should be: we give suspensions to them with the same criteria, irrespective of the reason (rule violations, low quality contributions, voting fraud, whatever). They shouldn't be let off the hook just because their kids. We hold them to the same behavioral standards. Then, as status quo, we start with short day/week penalties, which increase in duration. But once the duration reaches 2 months, I think it should stop increasing. If the person comes back to misbehave, we simply give another 1-2 month timeout. I'd like no lowering/raising of the trigger... just a restriction on the suspension length.
I also do not expect any changes in the automatic post ban... even if they're in middle school, they need to take signs that the questions aren't working, and since that mechanism is already quite gentle, it doesn't want changing. (Furthermore, I think that's automatic, so the system clearly can't guess approximate ages.