Slumdog Millionaire

The chaos and the constant noise and motion of Mumbai at the center of the film, (supported by a fabulous soundtrack) are contrasted with a deeper silent seeking. Describe what each of the main characters is seeking.

From what i saw, Salim was looking for his brother Jamal, and Jamal was looking for the girl, Latika; and then the soundtrack and the motion in Mumbai appears to give the movie more suspense and to contrast the silent seeking from the characters.

In the final scene, we see Salim and the choice he makes - filling the bathtub with money, etc. Why does he make this choice?

He helped Latika to escape, and then he killed (shot) Javed. After that, he filled the bathtub with money and then he died in that way because he always wanted to die with a lot of money and also he was sad about everything he made to his brother and he wanted to be excused.

This film weaves together nightmare and impossible dream. What do you take away as the most important message or impression from the film?

Each one of us can have a different impression of the film. But, mine was that, we should be proud of everything that we have and the persons we have with us. And also that there is a reason for everything that happens in our lives, and we cannot know what's going to happen next.
And the most important point, that we must not criticize the persons for their appearance, or make them "feel less", because at any moment and any time they can surprise us and be better than we are in different ways.