I never watched any of the films; I've never been big on audiovisual stuff. (I only get into fandoms for such if the canon has subtitles. *g*)

The thing I like best about personality typing systems is that they remind me that it's not that everyone else is trying to be like me and doing it badly -- they're being themselves extremely well!
That is an interesting use for them I haven't encountered yet! Also, what do you mean, other people aren't just imperfect imitations of me? Thinking about Hogwarts Houses, I doubt they'd have the same effect, because they're just "are you brave, smart, loyal/hardworking, or ambitious/evil?" and those aren't even archetypes, just adjectives of which most people are two or more.