I've been using Story Plus for over a year and just now upgraded to the full Creative Cloud. So first of all, I just want to confirm that my membership to CC includes Story. I'm fairly certain it does.
If that's the case then I would like to cancel my Story subscription so I'm not paying an additional $10 for no reason. I'm fairly certain there won't be a problem, as the files are linked to my email, but I'd just like to be sure. Will the cancellation affect my files?
You are right. Story Plus subscription cancellation will not affect your files.