in reply to Post-Posting Etiquette
Other than Editor Requests, we don't have generally accepted procedures for changing root nodes. (The ability to change posts depends, in the case of most root nodes, to being an editor. I assume you're talking about root nodes.)
I rather suspect that most editors ignore Editor Requests (by forgetting to look there periocally). If you post an SoPW question, then discover a goof, ask in the CB whether there's an editor around. I've fixed up several posts for people who've discovered a post-submit goof.
A conscientious editor will leave a note at the bottom of the post if the change is significant enough to affect the reading of any existing replies.