I’m not sure where this goes, but I feel like it’s a general writing topic since it’s more about writing style than characters. Initially I only wanted to write this story through my MC’s viewpoint. However, several of the other characters have really interesting plot lines that feel like a waste just to recap. But they don’t have story enough to be viewpoint characters. That’s when I thought of Interview with the Vampire, and possibly attempting something in that style. If you haven’t read it, the story is written in third person, but also in first person, as the vampire tells his tale to the reporter. Although it would happen several times during the story, I’m worried this would be too jarring. In Interview, almost the entire novel is the interview. Whereas in my novel, it would primarily be from my MC’s viewpoint, and then suddenly someone else for a chapter as they tell him what has happened. The thing is, I feel like just switching viewpoint character is just as bad for my story. I don’t want the reader to know more than my character (me knowing things about the story while the main character is clueless are one of my pet peeves). Also, each character would just suddenly have a chapter without explanation. Any thoughts on this? Other ways to do it?
I would say that if you don't like the idea of switching viewpoint - don't do it. And I say that as someone personally attempting a George R.R. Martin-esque multi-viewpoint mess. I hop around between viewpoints personally because I know that there's not another way to tell the story. I also know it's a minefield and that I'm putting extra work on myself, and if you chose to do that, youd have to do that extra work as well. If you want to include snippets of interviews or news stories, that's different. A lot of sci-fi or fantasy occasionally cuts in with little snips of some sort of fictional source document. One example is Asimov's "Foundation" series - each novel is a series of shorter vignettes, and each vignette opens with an article from the fictitious "Encyclopedia Galactica" describing the characters about whom you are about to read (the construction of the Encyclopedia was ostensibly the reason the Foundation was set up, and quoting from the finished text implies that it's eventually completed some time long after the action). There are ways of working in stuff like that without breaking viewpoint, because in theory you're not cutting viewpoint so much as your including quotes from a false news source that exists in-world.
The Poisonwood Bible tells the story through three sisters and the mother, all as first person POVs. It's different than you seem to be asking about but you should take a look at the style and see what you think. My book starts with one character telling the story. In the last few chapters I change to one of the other character's POV because I need to tell some parts of the story the protagonist is not present during. He's the transition character between the first and second book which has a different main character and it's told mostly in that third person's POV.
The Sherlock Holmes stories are not narrated by the great sleuth. Also check out Ian Fleming's The Spy Who Loved Me.