You're over-thinking trademarks. A trademark is a brand. They're protected to prevent unfair competition.
Therefore, as long as it's immediately clear that you're not trying to use someone else's brand (trademark) as a draw for your product, you should be as safe...to the extent that the trademark owner's lawyer understands the law.
If you're thinking about it, really check with a lawyer, since trusting anybody here isn't going to help you if you're sued.
However, the guideline I'd use is, if I saw this book (or other product) as it's normally sold (full picture of the cover and the "above the fold" logo area), is there any other group I might think produced it? If there's any chance a consumer might make the mistake of thinking that "Captain Marvel Adventures" was produced by Marvel or DC, then it's almost certainly going to be viewed as trademark infringement.
Normally, that's ONLY as the product is sold, though. Once you've gotten through the sales process, I don't understand there to be any trademark problems. The main character can drive a BMW in a novel and hate it or love it, without BMW asking you to cease and desist, for example.
Though they might take issue if you use the word "Beemer" to refer generically to any high-end car, since that could be viewed as an attempt to genericize the mark, however. Xerox used to be big on that. And Microsoft is currently going through some growing pains in finding out that "Windows" isn't a protectable trademark in some jurisdictions, since the term has been generic in many fields for, y'know, centuries (and in computers since the Xerox Star report).
