Did you like it? I really did like it, I suggest you to read book as well if you haven't read it. I was really mad that book&movie were so short. They could at least add something after Gale and Katniss conversation.
Killing each other? As you see in the movie (also in the book) tributes are helping Peeta&Katniss, (well they are actually saving Peetas life as he can't do anything /fp and Katniss always has to save him), but there still are some tributes for example District 1 tributes brother&sister and Enobaria, Brutus. They all could play together and make a plan to kill President and do something bad for Capitol. YES I understand that Capitol would try to kill them, but it would help revolution a lot. But , its just me.