The deck is stacked everywhere, but so what? Get over it. An engineer has the ability to improve the world by building better things without resorting to destruction.
Keeping them in check just delays the inevitable meltdown.
The societal problem is convincing everyone that they're a genius. When life hands them less than the best and they have to overcome it, they just get disgruntled, because "they're too smart" to deal with it.
Parents, remind your children that there's always going to be someone smarter/faster/stronger/etc than them, and that they should focus on doing as well as they can with the circumstances they're given. There's more good in being the best you can be than there is in being the best; for a lucky few, those things are identical, but for the rest of us they aren't.
However in this country (the US) the gaps are wider and the deck is stacked more than in any other industrialized nation in pretty much every category.
Try complaining against the state in an industrialized nation like China.
Is it just that they have better control of their media (so we don't hear about it), better control of the people (so they don't get a chance to do it), or something else?
By the way, there were also some incidence of pupils shooting up their schools in recent years in Germany. I guess you are just much more exposed to American incidents than to the rest of the world. (E.g. have you heard of the whole ugly neo-nazi stuff in east Germany in the 90ies? It still goes on, though at a much lower level of intensity. It's quite hard to find English language sources on the anti-asylum-seekers riots in Hoyerswerda in 1991 but http://www.jstor.org/pss/4146935 is on.)
In terms of impact, you're probably right. I think it's likely that 9/11 is the first news story to have reached half the world's population in a few hours. However, there are pre-modern events that rival it in terms of potential impact. I can't think of any from the 11th century, but the Defenestration of Prague comes to mind, as would the Gunpowder Plot had it succeeded.
Honestly if the Gunpowder Plot had succeeded, I have little doubt it would have turned into a massacre of Catholics in Briton and likely devolved into a full out war. Ireland would have received a full massacre for the guerilla war it had waged against Briton, and Spain would have likely come under full attack for supporting the Irish Catholics during that time.
It would be hard to see any result that isn't total war for a successful bombing. Ironically the plot was the worst thing to happen to Catholics but simultaneously the best outcome for the situation.