The metaphor "She was the spark that set the Districts alight with ideas" is found on page 159 of "The Hunger Games" by Suzanne Collins. In this passage, Katniss is referring to her sister Prim's innocence and impact on the rebellion.
Yes, "holding your tongue" is a metaphor for keeping your mouth shut. That is a metaphor used in The Hunger Games.
Pamen
All the districts have to do the hunger games as they all rebelled against the capital. The capital use the hunger games to scare the districts and stop them rebelling again as they don't know if they can control them again. So it is used to stop them fighting back its there weapon against them.
The Capitol (they control the hunger games and are not required to enter the reaping)
Tributes
All 12 Districts go to the Hunger Games. I am not surprised they do have people that go to the games.
The Hunger Games are held by the Capitol as a reminder to the districts of their rebellion and how badly it ended for them.
Some districts have a lot more volunteers then others. In district 12 there are hardly ever any volunteers for the hunger games, so it is mostly allowed. In the higher districts it is done a lot, so they would have to limit how many, and who can volunteer for The Hunger Games.
Yes there is
No, its only within the districts of Panem.
yes
the woods in the hunger games represent the freedom and danger facing the people of the districts if they were to leave where they were