Can I use the name “sk-nwalker” on a podcast where that creature is a villain in the book I’m covering? Or is that disrespectful and I should call it by another name?

You’re right in seeking guidance on using this taboo term. I appreciate you approaching this with caution.
 
Being Zuni and living near Navajo people, we were taught to be weary of animals, especially near sunrise or sunset when witches were more likely to be out.
 
Clearly you know this topic is taboo and can be thought to call them or bring bad luck to those who whisper their name or talk openly about them. Consider what meaning this has to you. Is this something you’re willing to risk or are there ways to creatively and respectfully talk around the term? If you think so, then write these down and practice them before you go live to avoid talking hastily or disrespectfully.
 
Continue to do your research and certainly consider if this book is written in a respectful way that does not glorify or use the term as shock value for its readers. Make sure you take care of yourself during this process and keep in mind that some elders or other community members who may choose not to engage in these conversations. Be respectful of that.
 
Keep in mind what authors/ artists and materials you promote on your podcast. As always, let your integrity and authentic self shine.
 
Best of luck!
 
Auntie Manda