If you really want to get a better understanding of how your characters will react in different situations, try writing a scene in which multiple characters are present when something important happens. Write the scene multiple times, from the view point of a different character each time.
Provide them with the same general information, but take careful not of how they interpret and react to it differently. This can tell you more about the characters than you thought you knew, in addition to providing you with an idea of the most effective way to write the scene. Is it best presented though the viewpoint of your protagonist, or someone else in the room?