1). Several points:
I would be careful not to draw the superficial parallel to communism. IMHO the book actually illustrates the dangers of excessive corporatism, or fascism. The people in the districts of Panem never operate under the illusion that that the society's wealth is owned collectively; to the contrary, they are made painfully aware from the get-go that NOTHING belongs to them. It all belongs to the Capitol. The tributes are sent to the games as an ongoing reminder of the district's loss to the capitol, and their sub-class status.
The Capitol is obsessed with living the high life, and endless entertainment - with very little regard to the people who provide that lifestyle.
My younger teen drew the analogy that we in the US are the Capitol, and the 3rd world countries are the districts (sad). Where do those Ipads come from? And cheap toys? At what price (to the people who produce them) are those things provided?
The districts are also partitioned off so that each one produces one part of the economy. Therefore they are at the mercy of the Capitol for other staples of living. Again, does that sound like global capitalism to you?
And what about the obsession with "reality" entertainment? That is another creature of excess consumerism (which stems from capitalism to the extreme).
Have you ever wondered where the strongest housing markets are in America? If I remember correctly three out of the top four are found right near WASHINGTON D.C. Hmmmm . . . "Capitol" anyone?
My take-away from the book: THE PEOPLE ALWAYS HAVE THE POWER - we just have to have the courage to exercise it. We must never lose touch with our humanity.
2) I wouldn't have a problem with mature 7th graders participating in that activity. Of course I would want to guide them through it, discuss it, etc.
PS: I'm not against capitalism. What I'm opposed to is excessive crony capitalism . . . I'm also very pro-individual rights.