When you are telling a story in third person, should you as the narrator take on the personality and/or emotions that the main character of the scene has?
I'd say it actually depends on the story. If it's like grandpa telling stories in 3rd person to little kids, the emotion would be perfect. But in general, if you yourself are taking on the role of the narrator, I don't think you would. Let the character express his/her own emotions.
It depends on how involved the narrator is in the story. Sometimes the narrator is uninvolved and distanced; sometimes the narrator shows bias in favor of the POV character. My narrator is basically uninvolved, but often shows a slight bias toward the viewpoints and beliefs of the current POV character when the story is really getting into that character's thoughts. (Though this is mainly because, as the POV character, it has to be shown that the story is from their POV, and narration is the only way to do this in third person.) If the story isn't getting into a character's thoughts, then the narrator will of course be more distanced and unbiased. How much the narrator gets involved in the POV character's mindset depends on what that part of the story currently requires. Sometimes you want a closeup shot, sometimes you want one from a distance. It depends on how you want to tell the story, though I would never say there's a point when the narrator and the third-person POV character become the "same" person. It's best if they're kept separate to at least some degree or the story could end up becoming a Mary Sue or some sort of authorial wish-fulfillment.
IT depends on what your long-term goal for the story or stories are. My narrator works the way he/she does because before I even started my series I knew how it would end... So, as long as you have the answers ahead of time for yourself, the narrator can be involved or distant, just depends on your need.
