I am still a newbie in hugo obviously. I learned that hugo new posts/post1.md creates a new post, but I can’t find anywhere how I can delete a post through the hugo binary?? Or should I just go to ~content/posts/post1.md and delete it?
The Hugo binary doesn’t provide a command to do that. As Bud already said just delete the file.
With the cross references I was referring to the relref, ref shortcode that allows you to link (headlines in) other content files. But Hugo would warn you anyway if the link is broken due to the absence of the given content file.