Editing, like shooting angles, is what separates a boring video from an interesting one. While editing your film, you don't want to make it to flashy, but pleasing to your eyes. You don't want it to be cheesy with bad special effects, but it should have some to cover up your mistakes. IF you edit your video well, it will look very professional.
If you shot a video with just one angle, it would be pretty boring. When you shoot a video you should get in different shots and angles so you can see someone's perspective. In the NBA they have cameras in the backboard to see players when they dunk. In the NFL they have cameras in the pylons to see if the players got their feet in bound. It also makes it a lot more interesting to look. If you get shots like medium and wide you can show the setting. If you do opposite you can really show your main character. Shooting angles is what makes your video different from other, boring videos.
Interviewing lets journalists get down to a personal level with the interviewees. It let's us see their side of the story. We can also get a real life experience of what we are interviewing them about. They let us get a personal connection to them and to the story.
In order to know the background and information for the story you are reporting on, you need to research the topic. It would be bad for you to go into a story knowing absolutely nothing about it. You would have no questions or even a base of what you would report about. Research is how you formulate your story, therefore it is a key part of journalism.
Shooting B-Roll is a way to see people without them seeing you. It is a way to observe someone or something in its natural environment. B-Roll is important for broadcasting so people can see real people doing real things. Without B-Roll you would just see actors doing what they're told to do.