You're making it very easy on yourself if you just say "oh, it's one step removed, that's okay then". Either RPF Is sketchy, then fictional canons about actual real people are exactly the same and writing fic about them is sketchy by association. Or fictionalization of real people in books and movies is okay. But then RPF is okay too. You can't have it both ways, be all "well, someone else did it first" and wash your hands in innocence.